Part IV is on _Sigillaria_ and _Stigmaria_, the "_Sigillaria

described being _S. vascularis_, since identified with _Lepidodendron selaginoides_, or _L. vasculare_, if we maintain Binney's specific name.

Binney was not a great theoriser. His object was rather to provide material for the botanists, he being essentially a geologist. This he did admirably, for his monograph is illustrated by magnificent drawings from the hand of Fitch, the famous botanical artist.

Binney stood more under the influence of Brongniart than did his successor Williamson.

I now go on to my principal subject. Williamson's father, John Williamson, originally a gardener, was well known for his researches on the Natural History of the Yorkshire coast, and was for 27 years curator of the Scarborough Museum. Previously to that, John Williamson kept a private museum of his own, and it was in the room next to this that William Crawford Williamson was born on November 24, 1816. John Williamson's cousin, William Bean, was also an active local naturalist, known especially for his work on the Yorkshire Fossil Flora; the genus _Beania_ is named after him.

Our Williamson's mother, born Elizabeth Crawford, was the eldest of 13 children of a Scarborough jeweller and lapidary. Young Williamson used to spend much time in the Crawford's workshop, watching them cutting and working with the diamond the agates from the gravels of the coast. "A youthful training," he says, "which became of the utmost value to me more than a third of a century later, when scientific research required me to devote much of my own time to similar work[121]."

In 1826 the famous William Smith and his wife established themselves in the Williamson's house, and stayed there for two years. Williamson's early recollections of the "Father of English Geology" must have been inspiring. His father was also a friend and correspondent of Sir Roderick Murchison.

The appearance of Phillips' classic volume, _Illustrations of the Geology of Yorkshire_, in 1829, gave young Williamson his first introduction to true scientific work. His father at once set to work to name from this book the fossils he collected, and his son was called in to help. "My evenings throughout a long winter were devoted to the detested labour of naming these miserable stones."--"Pursuing this uncongenial task gave me in my 13th year a thorough practical familiarity with the palaeontological treasures of Eastern Yorkshire. This early acquisition happily moulded the entire course of my future life[122]."

Those were not the days of the half-educated. Young Williamson, in addition to his special scientific training, had the advantage of a classical education, at schools both in England and France. The French part of his education was not altogether a success, for most of the boys at the school were English.

Passing through London on his return he had breakfast with Sir Roderick Murchison, who took him to the Geological Society. This was in March 1832, when he was little more than 15. Certainly his entrance into the scientific world was made easy for him. Would it be made equally easy now for a boy in a similar position? In the same year, 1832, Williamson was articled to Mr Thomas Weddell, a medical practitioner at Scarborough. While with him, he continued to pursue Natural History as a recreation--bird-collecting for example, and also botany. He writes, "I was then forming a collection of the plants of Eastern Yorkshire, as well as trying to master the natural classification, which was already beginning to supplant the Linnean method, so long the one universally adopted[123]."

A memoir on the rare birds of Yorkshire was communicated to the Zoological Society of London--an early work though not quite the earliest. While with Mr Weddell, Williamson contributed a number of descriptions and drawings of oolitic plants to Lindley and Hutton's _Fossil Flora_. He tells us how the drawings had to be made in the evenings on Mr Weddell's kitchen table. The plants he illustrated had for the most part been collected by his father and John Bean in a small estuarine deposit at Gristhorpe Bay. More than 30 species were thus recorded by him.

He also made diagrams to illustrate some lectures on Vegetable Physiology given by Mr Weddell at the Mechanics' Institution. It is rather surprising to find that such a course was given in a country town during the early 'thirties. Probably the learning displayed was not very deep, for Mrs Marcet's _Conversations_ seem to have been the chief authority.

In 1834-36 Williamson published important papers, determining geological zones, from the Lias to the Cornbrash, by means of their fossils; subsequently he extended his zoning work up to the Oxford Clay.

The opening of the Gristhorpe tumulus in July 1834, when a skeleton, of the Bronze Age, was found in a coffin fashioned out of the trunk of an oak-tree, gave occasion to Williamson's one contribution to archaeology. His memoir was reprinted in the _Literary Gazette_ for October 18, 1834 (still before he was 18). This was through Dr Buckland's influence; in a letter to Williamson he said, "I am happy to have been instrumental in bringing before the public a name to which I look forward as likely to figure in the annals of British Science." A second and third edition of this paper were called for.

In September 1835 Williamson was appointed curator of the Museum of the Manchester Natural History Society, and so began his long connection with the great northern town, lasting down to 1892. In those days the interest in the vigorous young science of geology was extraordinarily keen, and there was great activity, especially among the naturalists of the North, many of whom were working men. Williamson, about 1838, gave a course of lectures on geology at various northern towns, and thus raised funds for his removal to London, to continue his medical studies. It is interesting to find that Williamson, while at Manchester, helped to nurse John Dalton in his last illness.

While curator at Manchester, Williamson saw the rise of Binney as a geologist.

His remarks on the local study of botany at that time are interesting. "The botanical interests of the district were chiefly in the hands of the operative community. The hills between Lancashire and Yorkshire swarmed with botanical and floricultural societies, who met on Sundays, the only day when it was possible to do so[124]." Some of these men must have had an excellent education, as shown by the good English they wrote, as for example Richard Buxton, a poor working man, author of a standard _Botanical Guide_. The society to which Buxton belonged had, in 1849, existed for nearly a century. It may be doubted whether an equal enthusiasm for science still prevails in that or in any part of England.

In September 1840 Williamson went to London to complete his medical training, and entered University College, making the acquaintance of Prof. Lindley, who had for so long known him only as a correspondent and collaborator.

Soon afterwards he was offered the post of naturalist to the Niger expedition, which he refused, and, as it turned out fortunately, for the journey proved disastrous. Stanger, of _Stangeria_ fame, took his place.

In 1842, having then returned to Manchester and started in practice, Williamson made his first attempt at microscopic work, having become interested in the Foraminifera of the Chalk. He also began to examine Confervae, Diatoms and Desmids, finding perhaps, as others have done, that the Fresh-water Algae give the best introduction to microscopic biology.

The work on Foraminifera became one of the most important in Williamson's career. In 1845 he wrote his valuable paper on microscopic organisms in the mud of the Levant. His work in this field culminated in his monograph of Foraminifera, issued by the Ray Society in 1857.

In 1851 Williamson was appointed Professor of Natural History, which included Zoology, Botany and Geology, at the new Owens College, Manchester. He tells us, "The botanical portion of my work was that for which I was least prepared"--"of the German language I was utterly ignorant[125]." The almost insuperable difficulties of a triple Professorship were at first met by spreading the complete course over two years, a sensible plan which was rendered impracticable by the more rigid requirements of examinations. It was not, however, till 1872 that a division of the duties of the chair took place; Williamson was then relieved of the geological teaching by the appointment of Prof. Boyd Dawkins; in 1880 the zoology was taken over by the late Prof. Milnes Marshall, Williamson thus retaining the very subject, botany, with which he had originally been the least familiar.

In addition to his peculiarly arduous duties as Professor, Williamson was a great populariser of science. He was one of the first two members of the Owens' staff to start, in 1854, evening classes for working men. He gave numerous scientific lectures at the Royal Institution in London and elsewhere, his greatest work in this field being his lectures for the Gilchrist Trustees. He mentions that from 1874 to 1880 he delivered 158 of these lectures in 61 towns, and he continued this work with equal activity for another 10 years. He was a vigorous and effective lecturer, who always interested his audience; he illustrated his lectures by bold diagrams, drawn by his own hand. In order to form any idea of Williamson's many-sided activity it must be remembered that he was all the time engaged in active medical practice, both general and special, for he was well known as an aurist. Yet he always found time for fruitful original research, often of the most laborious character.

Prof. Judd says, in a letter written to me in February 1911:

"I have often been struck by the fact that Williamson, appointed to an impossible Professorship of Zoology, Botany and Geology, managed to initiate _great movements_ in connection with _each of these sciences_.

"In Geology he was clearly the pioneer in the subdivision of formations into zones each characterised by an assemblage of fossils--Ammonites playing the most important part.... But Williamson did another great service to Geology.... Sorby visited Williamson at Manchester and learned the art of making sections which he applied with such success to the study of igneous and other rocks, becoming the 'Father of Micropetrography.'

"In Zoology, Williamson initiated the work done in the study of _deep-sea deposits_, by his remarkable memoir on the mud of the Levant, in 1845, when he was 29 years old. This led to his study of the Foraminifera (especially by the aid of thin sections) and to his monograph in the Ray Society on that group....

"Of his contributions to Botany through his sections of 'Coal balls' I need say nothing."

Prof. Judd makes no reference here to the papers which obtained for Williamson his F.R.S. in 1854. These embodied his researches on the development of bone and teeth, in which he demonstrated that the teeth are dermal appendages homologous with the scales of fishes. This important work dated back to 1842 and was inspired by his enthusiasm for the then novel cell-theory of Schleiden and Schwann.

The interest aroused by this investigation is shown by the fact that the great German anatomist Kölliker travelled to Manchester, about the year 1851, to see Williamson's preparations.

As regards Williamson's work as a botanist, in which we are chiefly interested in this course, his best contribution to recent botany was no doubt his investigation of _Volvox_, published in 1851 and 1852, in which he traced the development of the young spheres and the mode of connection of their cells, anticipating the results of much later researches.

He was a great lover of living plants; his garden and greenhouses at Fallowfield, his Manchester home, were of remarkable interest, and he was a keen gardener. At the British Association Meeting of 1887 one of his guests said that "most of the distinguished botanists of Europe and America were in the garden, and not one but who had seen something growing he never saw before[126]." Insectivorous plants and the rarer vascular cryptogams were specially well represented. It was from his private garden that his classes were supplied with specimens.

As we have seen, fossil plants engaged Williamson's attention in his earliest years, when as a mere boy he contributed to Lindley and Hutton's _Fossil Flora_.

His first important independent work in this field was his paper "On the Structure and Affinities of the Plants hitherto known as Sternbergiae" (1851), in which he proved, for the first time, that these curious fossils, resembling a _rouleau_ of coins, were casts of the discoid pith of _Dadoxylon_, or, as we should now say, of Cordaiteae--the first step in the reconstruction of this early gymnospermous family. This investigation, to which he appears to have been led almost accidentally, through some good specimens coming into his hands, brought him back, as he says, to his old subject of fossil botany. It was long, however, before he got fairly started on his great course of investigations on Carboniferous plants.

In the meantime he had returned to the Yorkshire Oolitic plants and, about 1847, published a paper in the Proceedings of the Yorkshire Philosophical Society, "On the Scaly Vegetable Heads or collars from Runswick Bay, supposed to belong to the _Zamia gigas_." His full paper, in which he maintained the Cycadean affinities of the flower-like fossils, was written soon afterwards, but met with a series of misfortunes, and was not finally published till 1870, in the _Transactions of the Linnean Society_, before which body it had been read in 1868. Williamson was admittedly right in connecting the floral organs with the so-called _Zamia_ foliage, and his interpretation of the complicated structure was as good as was possible in the then state of knowledge. The true nature of these fossils, now known by the name _Williamsonia_, given them by Mr Carruthers, could only be understood at a much later date in the light of Dr Wieland's famous researches on the American Bennettiteae, and has quite recently been made clear in a memoir by Prof. Nathorst. Perhaps, even now, some points remain doubtful.

Early in the fifties Williamson made some rough sections of a Calamite which came into his hands, and this was the beginning of his most characteristic line of work. A remarkable internal cast of a Calamite, figured by Lyell in his _Manual of Geology_ in 1855, led to a correspondence with M. Grand'Eury, now so famous as the veteran French palaeobotanist. Williamson at that time had no intention of entering on the serious study of Carboniferous plants, for Binney was already in the field. Grand'Eury's letter, however, caused him to look up his old sections, which he found differed from the Calamitean stems figured by Binney. Matters for a time moved slowly, and Williamson's specimen was only described in 1868 in the _Manchester Memoirs_. This fossil, which he named _Calamopitus_, is now known as _Arthrodendron_, and is a distinct type of Calamarian stem, intermediate between the common _Calamites_ or _Arthropitys_, and the more elaborate _Calamodendron_ of the Upper Coal Measures.

Williamson was now fairly started on his Carboniferous work. His first memoir on the Organisation of the Fossil Plants of the Coal Measures was communicated to the Royal Society on November 11, 1870. It is amusing to find that the secretaries objected to the memoir being called Part I, since it bound the society to publish a Part II! Nineteen Parts were published, the last in 1893.

The first memoir was on the Calamites, and controversy at once broke out. Williamson was from the first impressed by the manifest occurrence of exogenous, or, as we should now call it, secondary growth, both in the Calamites and the Lepidodendreae, groups which he was convinced were cryptogamic. The controversy with the great French school, headed by the illustrious Brongniart, is well known. As Williamson put it: "The fight was always the same; was Brongniart right or wrong when he uttered his dogma, that if the stem of a fossil plant contained a secondary growth of wood, the product of a cambium layer, it could not possibly belong to the cryptogamic division of the vegetable kingdom?[127]"

In England, however, the dispute was on different lines. "In August of 1871," says Williamson, "the British Association met at Edinburgh. At that meeting I brought forward the subject of cambiums and secondary woods in Cryptogams, with the result that my views were rejected by every botanist in the room." There followed a controversy in the pages of _Nature_, which is of some interest, as showing the state of opinion in England at that time. Williamson tells us in his autobiography the principle by which he was guided in his work: "I determined not to look at the writings of any other observer until I had studied every specimen in my cabinet, and arrived at my own conclusions as to what they taught." In spite of this excellent rule it is probable that he was at first unconsciously influenced by the views of Brongniart, which may have led him to attach too much _systematic_ importance to the occurrence of secondary growth. At any rate he proposed at the Edinburgh meeting "to separate the vascular Cryptogams into two groups, the one comprehending Equisetaceae, Lycopodiaceae and Isoëtaceae, to be termed the Cryptogamiae Exogenae, linking the Cryptogams with the true exogens through the Cycads; the other called the Cryptogamiae Endogenae, to comprehend the Ferns, which will unite the Cryptogams with the Endogens through the Palmaceae[128]."

It is curious to note in passing that his main divisions, so far as vascular Cryptogams are concerned, correspond to the Lycopsida and Pteropsida of Prof. Jeffrey, though the suggested relation to the higher plants would not be accepted by any modern botanist. In spite of Williamson's tactical error in weighting himself with a doubtful scheme of classification, and in spite also of a faulty terminology, it is easy to see now that he had the best of the controversy, for he knew the facts about the structure of the Carboniferous Cryptogams, which his opponents, at that time, did not. They stuck to generalities, and those who take the trouble to rake the ashes of this dead controversy will at least learn that dogmatism is not confined to theology!

An interesting point is that Williamson at that time spoke of Brongniart almost as an ally[129]. The conviction that the old Lepidodendrons and Calamites were "exogenous" then seemed to him of greater importance even than his belief that they were Cryptogams. The English opposition, however, was never really formidable, and so a change of front became necessary, to meet the attacks of the powerful French school. Williamson was an energetic disputant; not content with his numerous English publications, he published, in 1882, an article in the _Annales des Sciences Naturelles_, entitled "Les Sigillaires et les Lepidodendrées." This was translated into French for him by his colleague Marcus Hartog, whose assistance he greatly valued. He describes this vigorous polemical treatise as "flung like a bombshell among my opponents."

In time they came over, one by one, to his views, and even the most redoubtable of the French champions Bernard, Renault, before the close of his life, had made very considerable concessions to Williamson's side of the question. There is no need to dwell on the controversy; every student now knows that the Club-mosses, the Horse-tails and the Sphenophylls of Palaeozoic times formed abundant secondary tissues homologous with those of a Gymnosperm or a Dicotyledon; the case of the Sphenophylls shows that the character was not limited to arborescent plants then any more than it is among Dicotyledons at the present day. At the same time, as Williamson maintained, these groups of plants were, broadly speaking, cryptogamic. On the other hand it has been said by a distinguished botanist that in the Fern-series secondary growth came in together with the seed. This is not strictly correct, but it is true that the plants such as _Lyginodendron_, which Williamson in his later publications cited as Ferns with secondary growth, have turned out to be seed-bearing. Even among the Lycopods a certain proportion of the Lepidodendreae bore organs closely analogous to seeds. These partial concessions, which may now gracefully be made to the old Brongniartian creed, do not however really affect the importance of Williamson's results, which Count Solms-Laubach has well summed up in the following words: "It was thus made evident by Williamson that cambial growth in thickness is a character which has appeared repeatedly in the most various families of the vegetable kingdom, and was by no means acquired for the first time by the Phanerogamic stock. This is a general botanical result of the greatest importance and the widest bearing. In this conclusion Palaeontology has, for the first time, spoken the decisive word in a purely botanical question[130]."

To attempt a review of Williamson's work in fossil botany would be to write a treatise on the Carboniferous Flora. In every group--Calamites, Sphenophylls, Lycopods, Ferns, Pteridosperms, Gymnosperms--his researches are among the most important documents of the palaeobotanist, and to a great extent constitute the basis of our present knowledge. At the time he wrote, the wealth of his material was absolutely unrivalled, and its abundance was only equalled by the astonishing energy and skill with which he worked it out.

As regards the Calamites, he demonstrated, to use his own words, "the unity of type existing among the British Calamites," abolishing the false distinction between Calamiteae and Calamodendreae.

Among the Sphenophyllums (although there was at first some confusion in his nomenclature) he gave the first correct account of the anatomy, and of the organization of the cone.

Concerning the Lycopods, the greater part of our knowledge is due to him. He described the structure in ten species referred to _Lepidodendron_, besides other allied forms, and placed our knowledge of the comparative anatomy, once for all, on a broad and secure basis. His great monograph of _Stigmaria_, by some considered his best work, is still our chief authority for the subterranean organs.

In the Ferns he made important contributions to our knowledge of the group now familiar to botanists as the Primofilices of Arber. In particular his account of the plant now known as _Ankyropteris corrugata_ is still among the best we possess of any member of the family.

In Pteridosperms, to use the modern name, Williamson may fairly be called the discoverer of the important family Lyginodendreae. He appreciated their intermediate position, speaking of them, in 1887, as "possibly the generalised ancestors of both Ferns and Cycads."

As regards both Pteridosperms and Gymnosperms proper, attention may be specially called to his work on isolated seeds, in which he was surpassed by Brongniart alone. This field of investigation, long neglected, has lately been revived with striking results.

I hope that all students of fossil botany will have at least turned over the pages and the plates of Williamson's works, for only by inspection of the original memoirs can any idea be gained of his vast services to our science.

His remarkable skill as a draughtsman (for all his memoirs are illustrated by his own hand) is not always done justice to in the published reproductions as the fine examples of his original drawings, so kindly lent for the lecture by Mrs Williamson, will show[131]. At the time when Williamson's main work was in progress--from 1870 to 1892--geologists were probably more appreciative of its value than botanists. Happily, in spite of occasional trouble with Referees, none of his work was lost, the Royal Society going steadily through with all the nineteen memoirs which were entrusted to them.

The one botanist, who, up to the year 1890, estimated Williamson's work at its full value was Count Solms-Laubach, who makes the honourable boast that he knew Williamson's collection as no one else did.

Williamson's writings are not easy reading, especially for the modern botanical student, for the terminology is often unfamiliar, and the arrangement of the matter unsystematic.

It would be out of place to enter on a criticism of details, but it is necessary to call attention to the one serious mistake which ran through much of Williamson's work, though at the last he to a great extent corrected it himself. He was always too ready to interpret specimens of the same fossil plant which differed in size and anatomical complexity, as developmental stages of one and the same organ. Such differences among fossils are more often due to the order of the branch on the plant, or to the level at which a section is cut. This error led to some mistaken, and indeed impossible views of the process of development. I mention this partly because I have noticed the same fundamental mistake in the work of much more modern writers. "We are none of us infallible--not even the youngest of us," and among the latest fossil-botany papers I have read, I have detected the very same confusion between differences of size and differences of age, which constitutes the most serious blemish in Williamson's writings.

As is well known, Williamson in his latest independent work corrected, as regards the Lepidodendrons, on the basis of a laborious re-investigation, the chief mistake he had made as to their process of growth[132]; he thus displayed an openness of mind worthy of a great naturalist.

I first saw Williamson on February 16, 1883, when I attended his Friday evening lecture at the Royal Institution, "On some anomalous Oolitic and Palaeozoic Forms of Vegetation." I did not, however, make his acquaintance till six years later, when we met at the British Association Meeting at Newcastle-upon-Tyne, in 1889. This led to a visit to his house in company with Prof. Bower; it was on March 8, 1890, that I first had a sight of his collection. I find the entry in my diary: "Spent 7 hours over fossils, especially _Lyginodendron_ and _Lepidodendron_, preparations magnificent." I at once became an ardent convert to the cult of fossil plants to which I had hitherto been indifferent, though I must in fairness admit that Count Solms-Laubach's _Einleitung_ had done something to prepare the way. I well remember the state of enthusiasm in which I returned home from Manchester. A subsequent visit confirmed me in the faith, but it was some little time before I put my convictions into practice. In 1892 Williamson, then in his 76th year, resigned the Manchester Professorship and came to live near London. In the same year I migrated to Kew, and it was agreed that we should work in concert, an arrangement which received every encouragement from the then Director, Thiselton-Dyer. Williamson first came to the Jodrell Laboratory on Friday, December 2, 1892. Then, and on many later visits, he carried a satchel over his shoulder, crammed with the treasures of his collection. For some months he came pretty regularly once a week, afterwards less often. On these visits we discussed the work I had done on the sections during the interval, and sometimes our discussions were decidedly lively. In the end, however, we always managed to come to a satisfactory agreement. Our first joint paper (_Calamites_, _Calamostachys_ and _Sphenophyllum_) was sent off to the Royal Society, rather more than a year from the start, on December 29, 1893.

During the early part of 1894 Williamson came occasionally to Kew, and our discussions were renewed, this time chiefly on _Lyginodendron_. Our second paper (Roots of Calamites) was despatched on October 30, 1894.

After a considerable interval Williamson again visited Kew, on December 12, 1894, when we started on his _Lepidodendron_ sections, a subject on which we never published in conjunction. His last visit was on January 7, 1895. A few days later his health broke down, and though there were many fluctuations he was never able to come to the laboratory again. I saw him last, at his own house, on June 4th. On the 13th I read our joint paper on _Lyginodendron_ and _Heterangium_ at the Royal Society; on the 23rd he passed peacefully away.

If Williamson could have lived it would, I think, have given him great pleasure to see the success, in his own country, of the work which he inaugurated and the progress of the subject to which he devoted the last 25 years of his life. I am happy to believe that he felt in the evening of his days, that the period of comparative neglect through which his work had passed, was at an end. For myself, I may say that my work, since I knew Williamson, owes its inspiration to him. But quite apart from our scientific relations it is a great privilege to have known him. Though his many-sided activity, as physician, professor, popular lecturer, geologist, zoologist, botanist and artist involved an amount of work which to us of a less strenuous generation is almost inconceivable, Williamson was as far as possible from being the mere student. His personality was intensely human. He was a man of most decided likes and dislikes; his conversation was often brilliant, and sometimes vigorous to an almost startling degree.

The grand old race of all-round naturalists found in Williamson its worthy culmination, and we can only regret that, from the nature of the case, he can have no equal successor[133].

FOOTNOTES:

[119] Since these words were spoken the veteran leader of English Botany has passed away. A notice of Sir Joseph's career will be found in this volume, and the present writer has given some account of his work on fossil plants in an _Anniversary Address to the Linnean Society_, May 24th, 1912.

[120] The portrait of Henry Witham is from the original picture in the possession of the Salvin family, at Croxdale; a photograph of the picture was kindly obtained for me by Mr Philip Witham.

[121] _Reminiscences of a Yorkshire Naturalist_, p. 6.

[122] _Reminiscences_, p. 12.

[123] _Reminiscences_, p. 33.

[124] _Reminiscences_, p. 78.

[125] _Reminiscences_, p. 136.

[126] _Reminiscences_, p. 190.

[127] _Reminiscences_, p. 203.

[128] _Nature_, Vol. IV., 1871, p. 357.

[129] _Loc. cit._, p. 409.

[130] _Nature_, Vol. LII. 1895, p. 441.

[131] Three characteristic figures from these originals have been reproduced for this volume (Plates 22-24).

[132] Williamson, "On the light thrown upon the question of the Growth and Development of the Carboniferous Arborescent Lepidodendra by a study of the details of their Organisation." _Mem. and Proc. Manchester Lit. and Phil. Soc._, Ser. IV. Vol. IX. 1895.

[133] The portrait of Williamson is from a photograph kindly lent by Mrs Williamson, and taken, as she informs me, at Torquay in or about 1876, when he was about 60.

HARRY MARSHALL WARD

1854-1906

BY SIR WILLIAM THISELTON-DYER

Training at South Kensington--Cambridge--Germany--investigates coffee disease in Ceylon--his early investigations--appointment to Manchester and association with Williamson--Ward's brilliance as an investigator--Cooper's Hill--investigation of lily disease--leguminous root tubercles--symbiosis and the ginger-beer plant--the Croonian Lecture--the bacteriology of water--bactericidal action of light--Ward's "law of doubling"--appointment to Cambridge--mycopiasm controversy--infection and immunity--physiological varieties of Rusts--bridgeing species--illness and death--his record as an investigator--personal characteristics.

Harry Marshall Ward, eldest son of Francis Marshall Ward, was born in Hereford, March 21, 1854, but he came of a Lincolnshire stock, settled for some time in Nottingham. From unavoidable causes he left school at 14, but afterwards continued his education by attending evening classes organised under the Science and Art Department. To that Department, he owed indirectly the opportunity of a useful and brilliant career. His means were small, and his earliest aim was to qualify as a science teacher. He was admitted to a course of instruction for teachers in training given by Prof. Huxley in 1874-5. Although he must have derived from it a sound insight into the principles of zoology, the subject does not seem to have had any permanent attraction for him.

In the summer of 1857 Ward came under my hands in a course of instruction in botany which I conducted with Prof. Vines in the Science Schools at South Kensington, and from this time onwards we were in intimate relations to the close of his life. I can best tell the story as it came under my eyes. It contains much that could not easily be dealt with in any other way.

It was soon apparent that we had got hold of a man of exceptional ability. It must be confessed that the atmosphere was stimulating, and the conditions under which the teaching was carried on necessitated its being given at high pressure. I remember that on one occasion Ward fainted at his work, from no other cause, I think, than over-excitement. In the autumn of the same year he went for one session to Owens College, Manchester, with the object of continuing his general education. I learn that he carried off the prizes in every subject that he took up.

In the succeeding year I was glad to avail myself of the assistance of Ward as demonstrator in a subsequent course at South Kensington, which I undertook with Prof. Vines. Later in the year he became a candidate for and secured an open scholarship at Christ's College, where Vines himself was then a Fellow, and went into residence in October, 1876.

Ward took full advantage of his opportunities at Cambridge, and attended the teaching of Sir Michael Foster in physiology and of Prof. F. M. Balfour in comparative anatomy. The sound and fundamental conceptions which he acquired from the former manifestly influenced his work throughout life. He took a first class in botany in the Natural Science Tripos in 1879. His first published paper was the result of work in the same year in the Jodrell Laboratory at Kew. In this, which was published in the _Proceedings of the Linnean Society_, he seriously criticised and corrected that of Vesque on the embryo-sac of Phanerogams.

As was customary with our young botanists, Ward went to Germany for a short time, for purposes of study and to strengthen his knowledge of the language. He worked at Würzburg with Sachs, whose lectures on the physiology of plants he afterwards translated in 1887. There he continued his study of the embryo-sac in Orchideae, as Sachs subsequently testified, "zu meiner vollsten Zufriedenheit."

Before the end of the year Ward was appointed on the recommendation of Kew to proceed to Ceylon for two years as Government Cryptogamist to investigate the leaf-disease in coffee. The history of this malady is almost unique in vegetable pathology. A native fungus which had eluded scientific observation, and must therefore have maintained an inconspicuous and limited existence on some native host-plant, found a wider opportunity on the Arabian coffee plant and fell upon it as a devastating scourge. It was first detected in 1869 on a single estate; in 1873 there was probably none in the island entirely free from it. Mr (since Sir Daniel) Morris had shown that the plants could be cleansed by dusting them with a mixture of sulphur and lime. But the remedy proved of no avail as the plants speedily became re-infected. Morris had been transferred to another appointment in the West Indies and Ward's duty was to take up the investigation. This he accomplished exhaustively. He showed that the fungus (_Hemileia vastatrix_) was one of the Uredineae and that infection was produced by the wind-borne uredospores. Had the planters, as in Southern India, left forest belts between their plantations, the spores might have been filtered out and the disease controlled. As it was it spread like an unchecked conflagration. Ward also discovered the teleutospores; nothing has been added to our knowledge of its life-history beyond what he obtained. The result of his investigations was given in three official reports and in papers contributed in 1882 to the Linnean Society and the _Quarterly Journal of Microscopical Science_. It was no blame to him that his work led to no practical result. The mischief admitted of no remedy. The coffee-planting industry of Ceylon was destroyed and the Oriental Bank succumbed in the general ruin. Leaf disease has now extended to every coffee-growing country in the Old World from Natal to Fiji.

In a tropical country leaves supply a substratum to a little flora of their own, consisting of organisms partly algal, partly fungal, in their affinity. Ward, who had already developed his characteristic habit of never neglecting any point incidental to a research, carefully studied them, in order both to ascertain how far their presence affected the health of the leaf itself and to work out their life-history. The outcome was three important papers. One on Meliola, an obscure genus of tropical epiphyllous fungi, belonging to the Pyrenomycetes, was published in the _Philosophical Transactions_ in 1883. Bornet's classical memoir published in 1851 had been the authority on the subject. Ward was able to fill up "large gaps in the knowledge of important details." Another paper published in the _Quarterly Journal of Microscopical Science_ in 1882 on an Asterina illuminates an allied organism. But the crown of all Ward's Ceylon work was the splendid memoir on a Tropical Epiphyllous Lichen which was published by the Linnean Society in 1883. In this he, I think, cleared up much that was obscure in the _Mycoidea parasitica_ described by D. D. Cunningham. Having myself communicated the paper, I shall always remember the pleasure with which I undertook in Ward's absence to give an account of it. He solved the problem with convincing completeness; he extended Schwendener's lichen theory to a group of obscure epiphyllous organisms of which he afforded, for the first time, a rational explanation. The success with which this was accomplished placed him at once in the first rank of mycological investigators.

De Bary was the leading authority on Uredineae; and in 1882 Ward paid a short visit to him at Strasburg to confer with him on his coffee disease work, the accuracy of which de Bary entirely confirmed. There he made the acquaintance of Elfving and completed his Meliola paper.

The outlook for Ward was now precarious. Fortunately, I found myself sitting next to Sir Henry Roscoe at a Royal Society dinner, and I suggested that Ward, as an old student of Owens College, would be a fitting recipient of a Bishop Berkeley Fellowship for original research. Principal Greenwood recorded the fact that "the very important results already achieved by Mr Ward in Ceylon, in the domain of the higher botany, led the Senate and the Council to make this appointment." In 1883, he was appointed Assistant Lecturer and Demonstrator in Botany, and, on the same testimony, "abundantly justified his election." It was a peculiar pleasure to him to relieve the veteran Professor Williamson by taking entire charge of Vegetable Physiology and Histology. His position was, in the same year, made secure by his election to a Fellowship at Christ's College, and he married the eldest daughter of the late Francis Kingdon, of Exeter, who was a connection of Clifford the mathematician.

The passion for research now completely possessed Ward and never left him for the rest of his life. He published papers which added much to our knowledge of the Saprolegnieae a group of fungi of aquatic habit, partly saprophytic and partly parasitic. It is interesting to note that he was particularly attracted by the mode in which the hyphae attack the tissues on which they prey. This was a matter on which he subsequently threw an entirely new light. He made the interesting discovery of an aquatic Myxomycete, such a mode of existence being hitherto unknown in the group, and worked out its life-history. But his mind had now become definitely fixed on the problems presented by plant diseases, and they remained the principal occupation of his life. In their widest sense these resolve themselves into a consideration of the mode in which one organism obtains its nutriment at the expense of another. This ranges from a complete destruction of the host by the parasite to a harmless and even advantageous symbiosis. He was thus naturally led to an exhaustive study of the literature of the Schizomycetes, and contributed an article on the group in 1886 to the _Encyclopaedia Britannica_, which, for the time at any rate, gives the best account of it, certainly in English, and probably in any other language. When he supplemented this in 1902 by the article on Bacteriology, it was largely to give an account of his own important discoveries. In the earlier one, he had pointed out the difficulties of a natural classification of Schizomycetes due to their pleomorphism, which Lankester had demonstrated in 1873. He returned to the subject in an article in the _Quarterly Journal of Microscopical Science_ in 1892. It may be noted that, in his British Association address at Toronto, he took occasion to put in their proper relation the work of Cohn and of his pupil Koch.

In 1885, the Regius Professorship of Botany at Glasgow was vacant by the transference of Prof. Balfour to Oxford. Ward was a candidate with the warm support of his fellow-botanists. It was thought that his Colonial services would weigh with the Government; but other influences were at work in favour of another candidate, whom, however, the University refused to accept. A deadlock ensued, which was only solved by the Government finally refusing to appoint either candidate. This was a great disappointment to Ward, which was in some degree mitigated by his appointment to the new Chair of Botany in the Forestry Branch of the Royal Indian Engineering College, Cooper's Hill. The utilitarian atmosphere in which he found himself was not very congenial to him. But he had at any rate at last some sort of adequate position and a laboratory to work in, and here he remained--not, I think, unhappily--for ten years. He was, as he had been at Manchester, a successful teacher, and had the gift of interesting his pupils, whom he used to bring weekly to Kew during the summer months to visit the Arboretum. In point of research, this was the period of much of his most brilliant work.

The study of Uredineae occupied Ward at intervals during his life. The reproductive organs are pleomorphic, and it is no easy task to ascertain with certainty those that belong to the same life-history. In a paper on _Entyloma Ranunculi_, published in the _Phil. Trans._ in 1887, Ward for the first time traced the germination of the conidia of an Entyloma, and confirmed Winter's suggestion that they were not an independent organism, but actually belonged to it. Incidentally he discussed the conditions which are favourable to the invasion of a host by a parasitic fungus. This raised the question of immunity, to which at intervals he repeatedly returned.

About the same time he published in the _Quarterly Journal of Microscopical Science_ the results of an investigation undertaken for the Science and Art Department on the mode of infection of the potato plant by _Phytophthora infestans_, which produces the potato disease. It was not easy to add anything to the classical work of de Bary, but it was ascertained that "the development of the zoospores is delayed or even arrested by direct daylight," and Ward's attention was attracted to the problem, which he afterwards solved, of how the hyphae erode the cell-wall.

The solution was given in 1888 in a paper in the _Annals of Botany_, "On a Lily Disease," which has now become classical. He discusses the fungus which produces it, and shows that the tips of the hyphae secrete a cellulose-dissolving ferment which enables them to pierce the cell-walls of the host. This ferment has since been described as cytase. He shows that its production would determine the passage from a merely saprophytic to a parasitic habit, and makes the suggestion that an organism might be educated to pass from one to the other.

An admirable research (1887) was on the formation of the yellow dye obtained from "Persian berries" (_Rhamnus infectorius_). A dyer had found that uninjured berries afforded a poorer colouring liquor than crushed. Gellatly had found, in 1851, that they contained a glucoside, xanthorhamnin, which sulphuric acid broke up into rhamnetin and grape-sugar. The problem was to localise the ferment which did the work. Ward obtained the unexpected result that it was confined to the raphe of the seed.

As early as 1883 Ward had attacked a problem which he pursued at intervals for some years, and which was fraught with consequences wholly unforeseen at the time. It had long been known that leguminous plants almost invariably carried tubercular swellings on their roots. The opinion had gradually gained ground that they were due to the action of a parasite. Bacteria-like corpuscles had been found in the cells of the tubercle, and it was assumed that they had played some part in exciting the growth of the latter. "No one had as yet succeeded in infecting the roots and in producing the tubercles artificially." Ward described, in a paper in the _Phil. Trans._ in 1887, how he had accomplished this. He showed, in fact, that a definite organism invades the roots from the soil, and finds its access by the root-hairs.

Lawes and Gilbert had long ago proved that the higher plants are incapable of assimilating free nitrogen. Hellriegel and Wilfarth had, however, shown in 1886 that leguminous plants carry away more nitrogen from the soil than could be accounted for. This Ward confirmed by his own pot-experiments, and satisfied himself that the excess could only be derived from the free nitrogen of the air. Hellriegel further concluded that the tubercles played an essential part in the process. Ward had no doubt that the bacteroids were the channel of supply. But he failed to get any proof that they could assimilate free nitrogen outside the plant. He suggested that their symbiosis might be an essential condition, and was obliged finally to leave it an open question whether the cells of the tubercles or the bacteroids were the active agents in nitrogen assimilation. He had already stated in 1887 that it is very probable that the bacteroids "may be of extreme importance in agriculture." But he was never satisfied with anything short of the strictest proof.

In 1890 Ward was invited to deliver the Croonian Lecture. He chose for his subject the relation between host and parasite in plant disease. He defined disease in its most generalised form as "the outcome of a want of balance in the struggle for existence." But the particular problem to which he addressed himself was the way in which the balance is turned when one organism is invaded by another. This is the most common type of disease in plants and a not infrequent one in animals. The first result reached was identical with that of Pasteur for the latter; the normal organism is intrinsically resistant to disease. It is an immediate inference that natural selection would make it so. Ward then discusses very clearly the physiological conditions of susceptibility, which he shows to be a deviation from the normal. He had already indicated this in the case of Entyloma. The epidemic phase is reached when the environment is unfavourable to the host but not so or even favourable to the parasite. He then attacks the more obscure case where there is no obvious susceptibility. This, he finds, resolves itself into a mere case of the struggle for existence: "a struggle between the hypha of the fungus and the cells of the host." It is more subtle in its operation but of the same order of ruthlessness as the ravages of a carnivore. Ward's account of the struggle is almost dramatic. The cellulose "outworks" are first broken down, as he had previously shown, by a secreted ferment. The "real tug of war" comes when the hypha is face to face with the ectoplasm. Its resistance is at once overcome by flooding it with a poison, probably oxalic acid.

War with attack and defence is a product of evolution. How did it come about in this particular case? Ward convincingly traces out the whole process. The normal plant obtains its food from inorganic material. But when opportunity offers it easily lapses into a condition in which it takes the material for metabolism ready made from the decay of others and becomes saprophytic. Ward shows that it is only a step to the attack on the living, and for the saprophyte to become a parasite, and he further shows that it can be readily educated to be so. He does not hesitate to suggest that the function of conidia in the complicated cycle of fungal reproduction is to form the cellulose-dissolving ferment. But now and again the host does not succumb to its invader. A truce is sometimes called in the struggle, and host and parasite are content to live together in a mutually advantageous symbiosis or commensalism.

Three years earlier, in 1887, Ward's attention had been drawn by a happy accident to the physiological aspect of symbiosis, and it never ceased to occupy his mind. It was well known that ginger-beer was made in villages in stone bottles. The fermentation was effected by the so-called "ginger-beer plant" which was passed on from family to family, but nothing was known as to how or where it originated. It seemed to have some analogy with the Kephir of the Caucasus. A specimen was sent to me from the Eastern Counties, and it stood for some time in the sun in my study. I noticed the vigorous growth accompanied by a copious evolution of gas. Ward coming to see me one day, I handed it over to him as a problem worth his attention. At the same time Prof. Bayley Balfour had examined it and concluded that it was a mixture of a yeast and a bacterium. Its study involved Ward in a very laborious research which occupied him for some years, and of which the results were published in the _Phil. Trans._ in 1892. It proved to be a mixture of very various organisms, every one of which Ward exhaustively studied. This required not less than 2000 separate cultures. The essential components proved to be, as Balfour had suggested, a yeast derived from the sugar and a bacterium from the ginger. Both were anaërobic; the yeast fermented cane-sugar with the copious production of carbon dioxide but little alcohol; the bacterium also produced carbon dioxide, even in a vacuum tube.

The action of the two components studied separately proved to be not the same as when they worked in concert. This was conspicuously the case with the evolution of carbon dioxide, which proceeded with such violence as to make the research attended with considerable danger. It is known that the action of ferments may be checked by the inhibition of the products formed. Ward pointed out that while the use of these might be advantageous to the bacterium, their consequent removal might be equally so to the yeast. This established the important principle of symbiotic fermentation and gave it a rational explanation. On the morphological side Ward showed that the ginger-beer plant is comparable to a gelatinous lichen, and, having resolved it into its constituents, successfully reconstituted it.

The new conception threw a flood of light on many obscure points in fermentation generally, and it is not surprising that Ward's work at once attracted the attention of the brewing industry. It led him to an even more fertile suggestion, that of metabiosis. It was known that the finest wine is sometimes produced from mouldy grapes. He regarded this as a case of one organism preparing the way for another. He returned to the subject in a lecture given at the British Association at Dover in 1899 and pointed out that in the Japanese manufacture of Saké, an Aspergillus prepares the way for the yeast. He also showed that metabiosis played an important part in nitrification.

Fungi cannot draw their nutriment from solid materials without first profoundly modifying them. They accomplish a large part of their digestion, so to speak, externally to themselves. This constantly occupied Ward's mind. He insisted on the part played in the process by ferments. The hyphae of Stereum (_Phil. Trans._ 1898) delignify the walls of the wood elements of Aesculus layer by layer, and then consume the swollen cellulose. He failed, however, to isolate the ferment which does the work. Nor was he more fortunate with the little known fungus Onygena, which grows on horn, hoofs and hair, setting free ammonia as a final product (_Phil. Trans._ 1899). That there must be some hydrolysis of keratin can hardly be doubted, for Ward established the remarkable fact that the walls of the hyphae contain no cellulose, but are composed of chitin. Onygena has, in fact, abandoned a plant for an animal nutrition. This would place the germination of the species at a great disadvantage. But he found that this difficulty was overcome by the spores which had been licked from the skin germinating in the gastric juice of the animal's stomach, and, when voided in the excreta, infecting a new host by accidental contact. In the case of both Stereum and Onygena he accomplished for the first time the difficult task of tracing their life-history from spore to fructification.

Ward had prepared himself for the study of bacteria, and in the nineties he undertook, with Prof. Percy Frankland, a prolonged research on behalf of the Royal Society as to the conditions of their occurrence in potable water. The reports of the results fill a thick volume, and the amount of work involved is almost incredible. The bacteriology was entirely due to Ward.

That bacteria are not an inevitable element in potable water is proved by their absence from that of deep springs. They are arrested by filtration through the earth's crust. In any river system they are comparatively fewer towards the watershed, and more frequent towards the mouth. The obvious conclusion is that they are derived from the drainage of the land. As it is known that the bacteria of cholera and typhoid are water-borne, it becomes a problem of vital importance to ascertain if river water is a possible means of distributing these diseases. Ward set to work to ascertain: (i) What was the actual bacterial flora of Thames water; (ii) if this included any pathogenic organisms; (iii) if not, what became of them? The labour required by the first two branches of the enquiry was enormous; he identified and cultivated some eighty species; the resulting answer to the second was happily in the negative.

As to the third, two facts were known. First, that river water, if stored, largely cleared itself of bacteria by mere subsidence; secondly, that Downes and Blunt, in a classical paper communicated to the Royal Society in 1877, had shown that exposure to direct sunlight is fatal to bacteria in a fluid medium. Ward showed that subsidence could not be entirely relied on, as the sediment might easily become the source of re-infection. The effect of sunlight required more critical examination.

It was known that the spores of anthrax were liable to be washed into rivers. Ward determined to study this as the most extreme type of pathogenic infection. As it is undoubtedly the most deadly micro-organism known, and Ward proposed to deal with it on a large scale, it implied no small degree of courage. He found that the spores of anthrax were effectually killed by a few hours' exposure to even the reflected light of a low winter sun. It was clear that this was due to the direct action of the light and not to any heating effect, apart from the fact that they will tolerate boiling for a few minutes. It was further shown that there was no foundation for the theory of Roux and Duclaux that their death was due to poisoning by products of oxidation of the food-medium. Proof of this, indeed, was hardly required, for Pasteur had shown that the bacteria floating in the atmosphere are mostly dead. Were it not so, no surgical operation would be possible. To the bactericidal effect of sunlight is equally to be attributed the absence of bacteria from the High Alps.

The next point was to ascertain to what rays the effect was due. The spores of anthrax are so minute that, when mixed in large numbers with gelatine, they do not affect its transparency, A plate of glass coated with the mixture is at first clear, but ceases to be so if kept in the dark, owing to the germination of the spores. Ward found, in fact, that a photograph could be printed with it, the darkening being the reverse of that of a silver plate. After experiments with coloured screens he completely solved the problem in 1893, with the aid of apparatus supplied by Sir Oliver Lodge and some advice from Sir Gabriel Stokes, by photographing the spectrum on such a plate. It was at once seen that the destructive effect was due to rays of high refrangibility, and, what was extremely important, extended to, and found its maximum in, the ultra-violet. The same results were obtained with the typhoid bacillus. He made the suggestion that the arc light might be used for the disinfection of hospitals and railway carriages.

Comparatively little was known of the life history of any Schizomycete. Ward therefore made a detailed and exhaustive study of that of _Bacillus ramosus_, the _Wurzel bacillus_ of German authors, which is common in Thames water, and bears a superficial resemblance to the anthrax bacillus, but is innocuous. It proved convenient for study, as it ran through its entire life history in from thirty to sixty hours at ordinary temperature. It forms long filaments, the growth of which Ward was able to measure under the microscope with great precision. On plotting out his measurements he obtained a regular curve, from which he found that, under constant conditions, the filament doubled itself in equal times. This he called "the law of doubling." It is the same as the so-called "law of compound interest," and leads to the expression of the growing quantity as an exponential function of the time, so that the time is proportional to the logarithm of that quantity. This relation has, of course, long been familiar in chemical reactions, but, as far as I know, Ward was the first to detect it in any vital process in a plant. This, which was in 1895, has, I think, been overlooked. Stefanowska has since, in 1904, obtained a logarithmic curve for the early period of the growth of maize, which doubles its weight every ten days, and the subject has since been pursued by Chodat and others.

In speculating on the cause of the destructive action of light on bacteria, Ward adopted the view of his friend Elfving, that it inhibited metabolic processes necessary to nutrition. He suggests that the "constructed metabolites" at the moment of assimilation are in a highly unstable condition, and liable to destruction by oxidation promoted by light. He points to the fact that plant structures are frequently provided with colour screens, which would cut off the blue-violet rays and check their action in promoting the rapid oxidation of reserve materials, and he quotes the suggestion of Elfving that chlorophyll itself may serve as such a screen against "destructive metabolic action in synthesis." Ward seems to have attributed little importance to the fact that substantially the same view had long before been put forward by Pringsheim, though received with little favour. His own view that when red and orange predominate in the screens their effect is protective, has since afforded a probable explanation of the colouration of young foliage, especially in the tropics.

It can hardly be doubted that the upshot of Ward's laborious investigations has had a powerful influence in deciding the policy of the future water supply of London. If we hear nothing now of obtaining it from Wales, it is because we know that even polluted flood-water if exposed in large reservoirs will rid itself of its bacterial contamination, partly, as was known already, by subsidence, but most effectually, as shown by Ward, by the destruction of its most deleterious constituents by the direct action of sunlight.

In 1895, Ward was called to the Chair of Botany at Cambridge. He was supported by a distinguished body of fellow-workers, and developed a flourishing school, in which every branch of the science found its scope. The University erected for it an institute which is probably the best equipped in the country, and in March, 1904, I had the pleasure of seeing Ward receive the King and Queen at its inauguration.

During the later years of Ward's life he returned to the study of the Uredineae. The scourge of wheat perhaps from the dawn of agriculture has been "Rust,"

"Ut mala culmos esset rubigo ... intereunt segetes";

and the loss inflicted by it throughout the world is probably not calculable. But the history of the Ceylon coffee disease is only too patent an instance of the injury a uredine can effect.

Eriksson, the most recent authority on the subject, had found himself quite unable to account for sudden outbursts of rust which it did not seem possible to attribute to the result of infection. In 1897 he launched his celebrated theory of the Mycoplasm. He supposed that a cereal subject to rust was permanently diseased and always had been; that the protoplasm of the Uredo-parasite and of the cereal, though discrete, were intermingled and were continuously propagated together; but that while that of the latter was continuously active, that of the former might be latent till called into activity by conditions which favoured it. Ward discussed the theory in his British Association address at Toronto, and was evidently a good deal impressed with it, but nothing short of actual demonstration ever convinced him; and when he proceeded to investigate the actual histological facts on which the theory rested he promptly exploded it.

It is interesting to note that Ward, as I know from correspondence at the time, had himself been embarrassed in investigating the Ceylon coffee disease by the same kind of appearance which had misled Eriksson. It is due to an optical fallacy. When the hypha of a uredine attacks a cell it is unable to perforate it with its whole diameter. It infects it, however, with a reduced and slender filament; this expands again after perforation into a rounded body, the haustorium. In a tangential section the perforating filament cannot be distinguished, and the haustorium looks like an independent body immersed in the cell-protoplasm and with no external connection. It requires a fortunate normal section to reveal what has really taken place. Ward was accordingly able, in a paper in the _Phil. Trans._ in 1903, to dispose conclusively of the mycoplasm. This cleared the ground of an untenable hypothesis. The complicated nature of the problem which still presented itself for investigation can only be briefly indicated. Sir Joseph Banks, whose scientific instinct was sound but curiously inarticulate, had pointed out that the spores entered the stomata, and warned farmers against using rusted litter. Henslow, one of Ward's predecessors in the Cambridge chair, had been confirmed by Tulasne in showing that the uredo-and puccinia-spores (of the barberry) belonged to the same fungus. De Bary traced the germination of the spores and the mode in which the hyphae invaded the host; the fundamental fact, which he observed but did not explain, was that the germinal filament, after growing for a time superficially, bent down to enter the tissues of its host. Pfeffer in 1883 discovered chemotaxis, the directive action of chemical substances on the movement of mobile organisms. De Bary had previously hinted that the hypha might be attracted by some chemical ingredient of the host plant. Myoshi, a pupil of Pfeffer's, showed finally in 1894 that if a plant were injected by a chemotropic substance a fungus-hypha not ordinarily parasitic might be made to behave as such and attack it.

In such circumstances it might seem that the host was not merely incapable of resisting invasion by the parasite but actually invited its attack. Nature is, however, not easily baffled in the struggle for existence. Attack provokes new methods of defence. Ward soon found himself face to face with "problems of great complexity," and these occupied the closing years of his life.

It had been ascertained in fact that the rust fungus is not, as was at first supposed, a single organism, but comprises, according to Eriksson, thirteen distinct species, each with physiological varieties, and that those which are destructive to some grasses and cereals, are incapable of attacking others. This necessitated a scrutiny of the nature of grass-immunity. In a paper communicated to the Cambridge Philosophical Society in 1902, Ward announced a conclusion which was as important as it was unexpected. He had more and more made use of the graphical method for presenting to the eye at a glance the result of a mass of separate observations. In this case he uses it with striking effect. He shows conclusively, as far as rust in brome-grasses is concerned, that: "The capacity for infection, or for resistance to infection, is independent of the anatomical structure of the leaf, and must depend on some other internal factor or factors in the plant."

Finally, he is led to the conclusion that "it is in the domain of the invisible biological properties of the living cell that we must expect the phenomena to reside." He pointed out the probability that light would be thrown on this from the action of chemotaxis, on the one hand, and from that of toxins and antitoxins in animal organisms on the other. This is a most fertile conception, which would, however, have required a good deal of verification, and this, unhappily, he did not live to attempt. But with characteristic ingenuity he pointed out the analogy between the infective capacity of uredospores and the prepotency of pollen, which had previously engaged the attention of Darwin. In a paper published in the following year in the Berlin _Annales Mycologici_, he announced a no less significant result. With his usual thoroughness in research he had cultivated side by side at Cambridge more than two hundred species and varieties of Bromus, and had watched the degree to which they were infected by rust under identical conditions. He found that though in the brome-grasses the rust peculiar to them is specifically identical its _forms_ are highly specialised. The form which attacks the species of one group will not attack those of another. Host and parasite are mutually "attuned." He termed this "adaptive parasitism." This raised the problem, which had first occurred to him in Ceylon, of how a parasite adapted to species of "one circle of alliance" can pass to those of another. Occasionally it happens that a uredo-form will infect a species where it ordinarily fails. In such a case "its uredospore progeny will thenceforth readily infect that species." Ward regarded this as a case of education. Working on this principle, he succeeded by growing the parasite _successively_ on a series of allied species which were imperfectly resistant, to ultimately educate it to attack a species hitherto immune. He called these "_bridgeing species_." He established, in fact, a complete parallelism between the behaviour of rust-fungi and that of pathogenic organisms in animals.

In the midst of this far-reaching research his health began to fail. In 1904 he had been appointed by the Council to represent the Royal Society at the International Congress of Botany held at Vienna in June of the following year. This he attended, though more seriously ill than he was aware of. On his way back he spent three weeks for treatment at Carlsbad, but receiving no benefit, he went, on the advice of Dr Krause, to Dr von Noorden's Klinik at Sachsenhausen (Frankfort). Nothing could be done for him, and he was advised to return home by easy stages. After a period of progressive and extreme weakness, borne with unflinching courage, the end came somewhat suddenly at Torquay on August 26, 1906. He was buried at Cambridge in St Giles's Cemetery on September 3.

From 1880, the year following his degree, Ward never ceased for a quarter of a century to pour out a continuous stream of original work. This alone would be a remarkable performance, had he done nothing else. But he was constantly engaged in teaching work, and he acted as examiner in the Universities of London and Edinburgh. With no less conscientiousness he complied with the demands which the scientific world makes on its members; he served on the Councils of the Royal (1895) and Linnean (1887) Societies; he was President of the Botanical Section of the British Association at Toronto in 1897, and of the Cambridge Philosophical Society in 1904. Beyond all this he found time to give addresses with unfailing freshness of insight; a lecture at the Royal Institution on April 27, 1894, on the "Action of Light on Bacteria and Fungi" was a notable performance; he wrote numerous articles of a more popular kind, and he produced a number of excellent manuals for students on subjects connected with forest, agricultural and pathological botany. Activity so strenuous almost exceeds the limits of human possibility.

Under the influence of Sachs, Ward might have become a distinguished morphologist. But his work in Ceylon led him into a field of research from which he never deviated. A survey of his performance as a whole, such as I have attempted, has a scientific interest of its own. His research was not haphazard. A continuous and developing thread of thought runs through it all. The fundamental problem was the transference of the nutrition of one organism to the service of another. Of this, in Ceylon, Ward found himself confronted with two extreme types, and of both he made an exhaustive study. In Hemileia it was ruthless parasitism; in Strigula advantageous commensalism. Bornet put Schwendener's theory on a firm foundation when he effected the synthesis of a lichen; Ward, in another group, did the same thing for the ginger-beer plant. In such cases the partnership is beneficial. The problem is to trace the process by which one partner gets the upper hand and becomes merely predatory. Ward inherited a strong taste for music, though I believe he never cultivated it. A musical simile may not inappropriately be applied to his work. In its whole it presents itself to me as a symphony in which the education of protoplasm is a recurring _leit-motiv_.

A few words must be said as to his personal characteristics. He had all the qualifications for the kind of research to which he devoted himself. He was singularly dexterous and skilful in manipulation. He was a refined and accomplished draughtsman, and was therefore able to do himself justice by illustration. He was rigorous in demanding exhaustive proof. This almost deteriorated into a defect. He would pursue every side issue which presented itself in a research, and was quite content if it led to nothing. He would say in such a case: "I will not leave a stone unturned." He was apt, too, I think, to attack a problem in too generalised a form. In his nitrogen work it always seemed to me that he wasted energy on remote possibilities, when a clean-cut line of attack would have served him better[134]. But his mind worked in that way, and he could not help himself. It was, I think, one of the most fertile in suggestion that I ever came across. In later years, in conversation especially, thought seemed to come quicker than words to express it. In this respect he reminded one of Lord Kelvin. In such a predicament he would simply remain silent, and slowly move his head. This habit, I think, explains the reputation of being "mysterious" which he seems to have acquired latterly at Cambridge.

He was not without the honour at home which he deserved, apart from the affection of his friends, and had he lived would doubtless have received it from abroad. He was elected F.R.S. in 1888, and received the Royal Medal in 1893. He was elected an Honorary Fellow of Christ's College in 1897, and received an Honorary D.Sc. from the Victoria University in 1902.

Botanical science could ill spare his loss at the early age of 52. But it may be grateful for 25 years of illuminating achievement. It might have been hoped that another quarter of a century would be allotted to one so gifted. But if the "inexorabile fatum" decreed otherwise, he is at least to be numbered amongst those of whom it may be said

"Felix qui potuit rerum cognoscere causas."

FOOTNOTE:

[134] NOV. 1911. I must guard myself against the implication that Marshall Ward's method was wrong in principle. For as pointed out by Prof. Turner in his "Address to the Mathematical and Physical Section" of the British Association at Portsmouth the maxim of "leaving no stone unturned" is identical with Prof. Chamberlin's "Method of Multiple Working Hypotheses." And what is at first sight an unlikely hypothesis may turn out to be the true one. Yet the rigorous application of the method is time-consuming and life is short. Some liberty of selection in testing the hypothesis that seems most probable must be allowed the investigator, and the instinct of genius may sometimes hit on the right one.

A SKETCH OF THE PROFESSORS OF BOTANY IN EDINBURGH FROM 1670 UNTIL 1887

BY ISAAC BAYLEY BALFOUR

Medicine and Botany--James Sutherland--enforced retirement--the Prestons--Charles Alston--his career--John Hope--Physiological leanings--Daniel Rutherford--Robert Graham--John Hutton Balfour--characteristics--Botanic Society of Edinburgh founded--appointed to Glasgow--transfer to Edinburgh--his numerous activities--laboratory teaching established--field excursions--Ecology--attitude to Darwinism--Alexander Dickson--work in Organography--his versatility.

My task in the warring against oblivion typified in these addresses is to speak about John Hutton Balfour of Edinburgh, one of the botanical teachers of the middle of last century, whose pupils were numbered by thousands, and whose active life bridged the period of the passing of the old and the birth of the new outlook upon science through Darwin's work; and in relation to what I have to say of him I propose to sketch briefly the stages and development of botanical teaching in Edinburgh from the date when systematised attention was first given to it.

Of the well-recognised fact that the study of Botany as a science has been, to begin with, dependent on Medicine my story furnishes an excellent illustration.

Only towards the end of the seventeenth century had the advance in practice of Medicine in Edinburgh reached a stage which gave urgency to a movement for the improvement in the training of the medical man, and the protection of the public from the attentions of inefficient votaries of the healing art. The foundation of the Royal College of Physicians in 1681 gave expression to the co-operative principle in the control of those who would profess Medicine; the creation of a Botanic Garden for the purpose of the cultivation of medicinal plants was the response in the direction of safeguarding the practitioner against the herbalist, and of giving him the advantage of a correct knowledge of the plants which were the source of the drugs he himself was to compound. Before this time, whilst many practitioners could grow drug-plants for themselves, and did so, the majority were at the mercy of the herbalist.

Two Edinburgh physicians--(Sir) Robert Sibbald and (Sir) Andrew Balfour--conspicuous among their fellows for their activity in promoting the cause of medical education and in the planning of the Royal College of Physicians, were the pioneers of the study of Botany as a science. Determined that the apprentices in Medicine should have adequate opportunity of learning the sources of many of the drugs in use, they acquired a lease of a small area of land in the neighbourhood of Holyrood Palace in which they arranged to cultivate medicinal plants, stocking it from their own gardens and from those of friends. They secured the services of James Sutherland--described as "knowing" in these matters--and placed their small garden under his care, with the obligation that he should instruct the apprentices and lieges in Botany. Sutherland cultivated his plants so well, and the instruction which he gave was so satisfactory, that ere long--no doubt through Sibbald's influence at Court--a portion of the Royal Flower Garden at Holyrood Palace was assigned for the cultivation of medicinal plants, and thither was transferred the collection already made in the hired area. Thus was founded, with the title of Physick Garden, a Royal Botanic Garden in Scotland, and the first Profession of Botany was set up therein by James Sutherland.

Of the earlier years of Sutherland we have no record. His success as a teacher induced the Town Council of Edinburgh--the body in which was vested at the time all the patronage of the University--to institute a Chair of Botany in the University, and to provide for practical teaching in another Botanic Garden belonging to the town. Sutherland was appointed to the Professorship and also to take charge of this new Town Garden, which, it may interest those who at the present day pass through the Waverley Railway Station to know, occupied a portion of the site of that station. Both these gardens were at some distance from the University, and apparently to save the time of the University students, perhaps also to create a teaching garden entirely within the jurisdiction of the College authorities, another portion of ground occupying a part of the Kirk o' Field, notorious as the place of Darnley's murder, was transformed into a herb-garden. Thus within a few years from the beginning of the movement for the providing of adequate facilities to students for learning about plants, three Botanic Gardens were made available.

During Sutherland's tenure of the Professorship teaching was given by him in these different gardens. It would appear, however, that Sutherland was at heart a numismatist, and whilst during the early period of his incumbency of office he had corresponded with many botanical institutions abroad, had introduced to the gardens new species of plants--many of them now established in the flora--and had published in 1683 a _Catalogue of the plants in the Physical Garden_, in later years his interest was centred in coins and medals. So great was the obsession that the patrons of the University, dissatisfied with his botany, compelled him to resign his Chair in 1706, to which they appointed Charles Preston, but Sutherland retained, until he retired in 1715, charge of the Royal Botanic Garden at Holyrood, of which by Royal Warrant he had been made Keeper with the additional personal recognition of Botanist to the King in Scotland. Thus the increase in number of gardens extended to the Professors, and from 1706 onwards to 1739 there were two rival Botanical Schools in Edinburgh--that of the Royal Garden, and that of the University.

Sutherland's place in relation to the development of scientific Botany in Scotland is that of pioneer in the teaching of systematic Botany from the living plants in relation to Materia Medica, and of first custodian and cultivator of plants for instruction in a public garden. His _Catalogue_ is now a book of some rarity--of great rarity in complete state owing to the number of cancel pages--and its reproduction at the present time would have interest alike scientific and historic. It is the first published record of a collection of cultivated plants in Scotland. It tells us the plants which were recognised as indigenous at its date, and from its record we can by correlation with information otherwise obtainable discover the time of introduction to Scotland of alien plants, and thus obtain a basis for gauging their influence on the native Flora as we know it now.

Charles Preston who stepped into the University Chair of Botany vacated in 1706 by Sutherland, was a medical man, an active correspondent of Sloan, Pettiver, and other scientific men in the south. On his death in 1712, after a short tenure of office, George Preston his brother succeeded him and filled the chair until 1739. Both of the Prestons seem to have been chiefly interested in the Materia Medica side of Botany and their teaching was on the lines of it. They are referred to by their contemporaries as men of botanical knowledge and of critical judgment, and their correspondence indicates that they were in touch with the botanical life of their time. Their work in teaching was always in rivalry with that at the Royal Physick Garden. At first no doubt it was effective and useful owing to Sutherland's neglect of his garden, but when a capable active scientific Professor was placed in charge of this Garden the case for such rivalry and duplication of effort ceased, and it is no surprise therefore to find that when a vacancy occurred in 1739 the University Chair was filled by the appointment of the King's Botanist in Charge of the Royal Physick Garden, who was then Dr Charles Alston. And this combination continues to our own time by mutual consent of the Crown and the University.

Sutherland's retirement in 1715 from the Royal Physick Garden four years before his death, which took place in 1719 when he was over 80 years of age, may have been determined by his incapacity for the duties, but it is probable other influences were effective especially as the office of King's Botanist was a Household Appointment and only during pleasure. Were I merely to tell of incidents in the history of Botany in Edinburgh I would here introduce the story of Dr William Arthur, Sutherland's successor at the Royal Garden. Arthur has no botanical claims, but had influential political friends whose zeal on his behalf he ill requited by becoming one of the leaders in the Jacobite plot to capture the Castle of Edinburgh in 1715. Having failed in the attempt he escaped to Italy, where in 1716 he died from a surfeit of figs! Ignoble fate for a King's Botanist!

A man of real distinction now comes into our botanical history in Charles Alston--a clear observer and experimenter.

Charles Alston, born 24th October, 1685, was the third son of Thomas Alston, M.A. of Edinburgh and M.D. of Caen, one of an old Lanarkshire family settled at Thrinacre Milne and connected with the house of Hamilton. After boyhood at Hamilton, Alston went to the University of Glasgow, but before the period for graduation his father died leaving a widow and large family poorly provided for and young Alston's University career was stopped. Through the intervention of the Duchess of Hamilton Alston was then apprenticed in 1703 to a lawyer with a view to his entering the Estates Office of the Hamilton family. But "anatomy and the shops were more agreeable to him than Style Books or the Parliament House" and his "genius inclined more to Medicine," and in 1709 when the Duchess took him into her service as her "Principal Servant," in which position "he had aboundance of spare time," "he ply'd close the Mathematics and whatever else he thought of use to a student of Medicine, particularly Botany." With this training Alston, through the influence of the Hamilton family, was made King's Botanist, Professor of Botany, and Keeper of the Royal Physick Garden in 1716 after the disappearance of Dr Arthur.

He adopted a wise course on succession. Having put the Garden in such order as he could he hied himself to Leyden in 1718 to study under Boerhaave, and returning thence in August 1719 he graduated in Medicine at the University of Glasgow, became Fellow of the Royal College of Physicians, and in June 1720 was able to begin his botanical lectures in the Garden, followed in November by a course on Materia Medica. These courses he carried on until 1739 when he was given the University Chair of Botany and Materia Medica, and the two Botany Schools were thus merged in one. Alston was now colleague of Munro, Rutherford, Sinclair, and other famous men who at this time were increasing the reputation of the University as a Medical School, and he continued to teach Botany and Materia Medica until his death in 1760.

Alston's teaching was mainly directed to the Materia Medica. His full course of lectures on the subject prepared for publication by himself appeared only as a posthumous work edited by his successor Dr Hope, and they reflect the best knowledge of the time, showing rational scepticism of the efficacy of many simples which experiment had not tested. Essays "On Opium," and "On tin as anthelmintic," and an "Index of Simples" published by him tell of his pharmacological investigations, to which his correspondence with Fothergill and others is also witness. The subject in this line to which he gave most attention and on which he wrote three dissertations based on experiments is that of Quicklime and Water--its efficacy in Calculus and also as an agent for keeping water sweet. From Alston, Stephen Hales, then in touch with the Admiralty upon questions of ventilation and other matters of sanitation, obtained early suggestions, and a long correspondence followed.

Alston, who had to earn his livelihood by medical practice, gave much time to the administration of the Botanic Gardens under his charge, and the elaborate lists which he prepared showing the disposition of plants in the Gardens, witness to his interest in their cultivation. His predilection in systematic arrangement was Tournefortian, and on the promulgation by Linnaeus of his "sexual system" in 1736, no writer was more trenchant than Alston in opposition to it, and by this he became widely known. His criticism was directed against it, not as a method of arranging plants by readily recognised characters, but from the standpoint of denial of the existence of sex. By various experiments as well as by argument, Alston endeavoured to disprove the necessity of the stamens for the development of fertile seed, citing cases of seed-production where no application of the "dust" from the stamens was possible--thus early recognising conditions which puzzled botanists for many generations afterwards and until the explanation of apogamy was supplied. One is tempted to wonder whether if the Linnaean system had not received the appellation "sexual" it would have roused the same condemnation from him as it did.

From his published work, notably the _Dissertation on Botany_ (1754) a translation of a portion of his earlier _Tirocinium Botanicum Edinburgense_ (1740), as also from some MS. of his lectures which still exist, we recognise the clearness and vigour of mind of Alston, and the precision of the man is made abundantly evident in the beautiful copper-plate writing in old script of his MS. Page after page is filled without blot or correction, and the whole systematised and arranged without flaw. Anatomical questions were dealt with by him in consonance with the knowledge of the time, mainly resting on Malpighi; but there is no rational treatment of physiological subjects, and this is the more surprising inasmuch as he was in intimate correspondence with Hales, and ought to have been acquainted with the fundamental experimental work of that physiologist. It may be that the fragments of record from which we have to judge are insufficient for correct appraisement, but on all the evidence we possess we must conclude that the two volumes of his _Materia Medica_ give us a picture of the direction of his teaching, and that Botany in the hands of its leading expositor in Edinburgh was at this period only a hand-maid to Medicine.

The advent of Alston's successor, John Hope, was the dawn of new things. The influence of the work of Hales had reached Edinburgh. Comparatively few botanists of to-day have heard the name of John Hope otherwise than as that of a correspondent of Linnaeus and protagonist in this country of his system of classification, for these are the claims to distinction assigned to him by the historians of British Botany; and if one reckons the value of a man's life-work in science by his published writings alone, that of John Hope would be a minimum; for only such papers as those "On Rheum palmatum," "On Ferula Assafoetida," "On Eriocaulon septangulare in Scotland," are extant from his pen. Yet John Hope was a botanist inspired by the spirit of research who obtained by scientific experimental work and explained to his pupils facts of plant physiology some of which the botanical world learned from other workers only a hundred years afterwards. It is difficult to account for Hope's reticence. It may be that he intended to give his work to the world in the book upon Botany which had engaged his attention for many years and of which the MS. was in great part ready at the time of his unexpected death in 1786--if so, the botanical world has been the poorer through the want of Hope's book.

But if Hope did not give cause by published contributions to natural knowledge for his recognition in promoting the advance of Botany, he has always been remembered with gratitude for services of administration which he was peculiarly fitted to render and which profoundly affected the study of Botany in Edinburgh.

John Hope was born 10th May, 1725. The son of Robert Hope, a surgeon in Edinburgh, whose father had become one of the Senators of the College of Justice with the title of Lord Rankeillour. Educated at a famous school in Dalkeith, John Hope, who early showed a liking for Botany, entered the University of Edinburgh as a medical student and became a pupil of Alston. His botanical inclinations tempted him to break the course of his medical studies in Edinburgh to study Botany under Bernard de Jussieu in Paris. Returning to Scotland he graduated in Medicine from the University of Glasgow in 1750, joined the Royal College of Physicians in Edinburgh and began medical practice, giving to Botany such time as could be spared from the many ties of a successful practice. In 1760 Alston died, and John Hope became his successor, first of all in 1761 as King's Botanist at Holyrood and subsequently as Professor of Botany and Materia Medica in the University.

Soon after appointment Hope recognised that to continue to hold "colleges" in Materia Medica meant spoliation of his botanical work. The time had come for a separation of the two subjects of Botany and Materia Medica. Problems of the former now pressing were not those specially relating to medicinal plants. He therefore managed to carry through an arrangement by which he retained a chair as Professor of Medicine and Botany, and a new Professorship of Materia Medica was created. The importance of this step for botanical progress was great--it was not merely a question of time occupied but of scientific outlook.

Another movement in the direction of concentration of effort in the cause of Botany was initiated by Hope early in his official career--that for the creation of a new Botanic Garden in a locality outside the immediate influence of town atmosphere, in which the collections distributed over the Holyrood and Town Gardens could be combined. He accomplished his design, and not only this, but obtained from the Crown a permanent endowment for the new Garden. This was no small achievement--but the omens were favourable, for those patrons of science the Earl of Bute and, later, the Duke of Portland, were in power when the Professor made use of the great influence which his family possessed to secure his ends. A spreading city in time made the location of Hope's new Garden unsuitable, and it was transferred to the present site; but it was the effort by Hope which gave the Botanic Garden, and through it Botany, a status among institutions requiring subsidy and maintenance by Government in Scotland, and the obligation so imposed has been upheld notwithstanding an attempt in later years on the part of the Government to get rid of it--an attempt which the short-sighted policy of the University nearly allowed to succeed.

Hope's duties in his University Chair required of him, in addition to his botanical work, clinical teaching in the Hospital, and he also engaged in practice--this for a livelihood--and took active share in the affairs of the Royal College of Physicians, of which he was President at the time of his death, which occurred in 1786. Botany could therefore claim but a portion of his time.

Having established the new Garden, he laboured with assiduity to lay it out effectively, and then to enrich it with plants. His own ardour and enthusiasm impressed others, and his pupils in all parts of the world contributed to making the Garden a renowned collection of the rarest plants. Here Hope met his students, and here he carried out his many physiological experiments which gave them instruction.

His teaching was comprehensive. Although no longer tied by the calls of his Materia Medica, Hope did not ignore the subject entirely, but plants in this relation were not the groundwork of his instruction. Systematic and descriptive Botany, recognition of herbs, still found a place in it. In Alston the most strenuous opponent of the Linnaean method had gone; it found in Hope a no less strenuous advocate, to whose influence its rapid adoption in this country owed much. To what extent Hope made excursions with his pupils, there is no evidence. His _Hortus Siccus_ and lists of plants with localities show that he was a field-botanist, and in correspondence with, if not more intimately acquainted with, the botanists who were working out the Scottish Flora at the period--such men, for instance, as Lightfoot, Stuart, Robertson. This we do know, that he encouraged his pupils to investigate the Flora of Scotland, giving yearly a gold medal for the best Herbarium, and Hope's "peripatetic pupils" is a designation met with in literature of the time. This aspect of Hope's teaching, consonant with the features of the botanical literature of the period, is that which has been commonly known. It is not however a complete picture. In Hope Scotland had a physiologist of originality and skill--who was not only informed upon the work of Hales, Duhamel, Mariotte and others, but who made his own experiments, clearly devised and effective, and whose catholicity is attested by his dealing with such problems as growth in length and thickness, effect of light and gravity, movement of water, healing of wounds, and the like. This physiology was an essential element of his teaching, and the effect upon students of contact with such direct wresting of truth from Nature must have been immense. Our knowledge of all this, only recently acquired, throws a new light upon Hope's character, and upon the influence which he appears to have exercised on the education of the time. The pity is that he left no published records, and that this bright period of brilliant research should have become obscured by the scholasticism inherent in the method of classification which he himself did so much to popularise.

In accordance with tradition, the Chair vacated by Hope was filled by the election of another medical practitioner in Edinburgh. Daniel Rutherford was born in Edinburgh 3rd November, 1749, the son of Dr John Rutherford, who as Professor was associated with Alston and others in the reformation of the Edinburgh Medical School. He was distinguished both as a classical scholar and as a mathematician, and after graduating M.A. at the University of Edinburgh, he entered on the medical curriculum, obtaining his diploma of M.D. in 1772. His thesis, when applying for the degree, was "De aero fixo dicto aut Mephitico," and by this he became famous through the distinction he established in it between carbonic acid gas and nitrogen, though he did not give nitrogen its name. The exposition he gave of his precise experimental work has been allowed to entitle him to be regarded as the discoverer of nitrogen, although shortly before the appearance of his thesis Priestley had practically, if less methodically, covered the ground. After graduation, Rutherford travelled in France and Italy, returning to Edinburgh in 1775 to begin the practice of Medicine, becoming Fellow of the Royal College of Physicians, of which he was afterwards President.

Rutherford was a chemist, and I have not discovered in any references to him expressions that would show he was at this period of his life interested in plants otherwise than as objects for his experiments in relation to the chemistry of the atmosphere. In seeking for a reason to explain his selection as Hope's successor in the Chair of Medicine and Botany, one may suggest either the general one of recognition of his scientific ability, or the more special one that in experimenting with plants he had been following on the lines of work so conspicuously developed by Hope. And of course at that time some general knowledge of Botany had to be the possession of every successful physician.

Like his predecessors, Rutherford had to undertake clinical teaching in the Hospital; he maintained also his private practice, and was keenly interested in the active literary world of his day in which his nephew (Sir) Walter Scott was a brilliant star. The Botanic Garden continued to hold its place as a scientific institution, and from the advent of William McNab as Principal Gardener in 1810, developed into one of the best known in the world. The recording of the plants of Scotland also proceeded apace; two of the Principal Gardeners of the Edinburgh Garden during Rutherford's Keepership--John Mackay from 1800-1802, and George Don from 1802-1806--being foremost in making known its floristic features, and their work Rutherford must have encouraged. From MS. notes of his lectures, I gather that the biological did not attract Rutherford, nor does it appear in the scanty records available that any special development of teaching equipment or of method took place during his tenure of office.

For some years before his death in 1819 Rutherford had been infirm; and speculation as to his successor had been rife. Robert Brown and Sir James Edward Smith were both spoken of. When the vacancy came Robert Brown refused it and Robert Graham, then Professor in the University of Glasgow, was appointed.

Robert Graham was born at Stirling 3rd December, 1786, the third son of Dr Robert Graham of Stirling (afterwards Moir of Leckie). After early education at Stirling, Graham was apprenticed in 1804 to Mr Andrew Wood, Surgeon in Edinburgh, and entered on the study of Medicine at the University, graduating M.D. in 1808. Thereafter he studied at St Bartholomew's Hospital in London for a year before settling in Glasgow, where he was also Lecturer in Clinical Medicine. During this period he published a dissertation "On continued Fever."

Botany in the University of Glasgow at this time had not reached the dignity of having a Professorship. It was attached to the Chair of Anatomy, but a separate lecturer undertook its teaching. To this lectureship Graham was appointed in succession to Dr Brown. This appointment was the prelude to his election as Professor in 1818 when the Chair of Botany was founded--a foundation which owed much to him through his influence with the Duke of Montrose, then Chancellor of the University, of whose house he was a cadet. One of the first efforts of Graham in his new position was directed to the completion of a scheme that was making for the formation of a Botanic Garden. In this he succeeded, and botanical teaching in Glasgow was thus equipped in 1819.

From this sphere in which he had initiated so much, Graham came to Edinburgh in 1820 as Professor of Medicine and Botany and was forced again to take up medical practice and clinical teaching in the Hospital, and in consequence to interest himself in the affairs of the Royal College of Physicians, of which he became President--all this, as in the case of his predecessors, in addition to his botanical work.

His first labour in relation to Botany was to transfer the Botanic Garden which Hope had made to a new site--that which it now occupies. Nearly two years were required to carry out the removal, to the success of which the skill of William McNab, the Principal Gardener, contributed greatly.

During the whole tenure of his offices Graham devoted himself to the affairs of this Garden, and often in the very practical way of supplying funds from his own resources to supplement the inadequate grants obtained from Government. It gave him the material for the description of many new species which were figured in the _Botanical Magazine_ and other like periodicals. This systematic botanical work was that which Graham cared for most, it was the backbone of his teaching, and all of his scattered papers deal with this aspect of the subject.

In connection with his teaching Graham developed specially the botanical excursion for the study of Field Botany, making it an integral part of his courses, and in furtherance of its aims travelling far through Scotland--a business of a much more arduous nature in days when railways and motors had not annihilated distance and provided all the comforts of civilisation within easy reach of every district. Graham had intended to publish a _Flora_ of Scotland as the result of his practical study of its plants, but it was uncompleted at the time of his death in 1845 after an illness of some duration during which (Sir) Joseph Dalton Hooker acted as _locum tenens_.

Another new method in his teaching was that of encouraging students to write essays upon subjects either practical or theoretical. In this he stimulated investigation. Students in these days had more time than they have now to devote to such things, and of their efforts some were sound pieces of research--the _Botanical Geography_ of Hewitt C. Watson first took form in one of these essays.

John Hutton Balfour[135], who succeeded Graham, was born in Edinburgh 15th September, 1808. The eldest son of Andrew Balfour, surgeon in the Army, who afterwards settled in Edinburgh as printer and publisher, in which business his enterprise was adequate to the venture of the _Edinburgh Encyclopaedia_ under the editorship of (Sir) David Brewster. Andrew Balfour was a grim old presbyterian of the stuff covenanters were made, and in the strict home environment which he created young Balfour early came into touch with theological dogma. The echo of these early impressions remained with him throughout life.

Educated at the High School of Edinburgh where he laid the foundation of sound classical scholarship--always his unobtrusive distinction--Balfour entered the curriculum for the Arts degree at the University. Before completing this he migrated to St Andrews in order to be under the influence of Professor Thomas Chalmers--the famous Divine, afterwards leader in the disruption that founded the Free Church of Scotland--in conformity with the desire of his father that he should become a minister in the Church of Scotland. But Divinity did not claim him and he returned to Edinburgh to begin the study of Medicine--a decision in face of family pressure which is tribute to the strength of purpose which characterised him and found expression frequently in after life.

At the beginning of this renewed Edinburgh curriculum Balfour attended the Botany course of Professor Graham in 1825, and obtained his first scientific instruction in Botany--a subject for which he had always shown fondness. Robert Dickson, afterwards Lecturer on Botany at St George's Hospital, London, was a fellow-student, and together they, in this and following years, made many botanical excursions about Edinburgh. With his fellows Balfour seems to have been _bon camarade_, acquired all the ephemeral distinction attaching to a facile writer of rhymed couplets for occasions, and as an inveterate maker of puns was in demand for the office of punster at the convivial clubs of the period. A mark of more serious attainment--he was President of the Royal Medical Society in two years. After graduation as M.D., when he also became a fellow of the Royal College of Surgeons in Edinburgh--his thesis for the former being "De Strychnia," for the latter "On Purulent Wounds"--Balfour went in 1832 to Paris to continue his medical education, studying there under Dupuytren, Lisfranc, and Manec. Returning, he settled in Edinburgh in 1834 and entered on practice, becoming assistant within and without the University to Sir George Ballingall, Professor of Military Surgery. Amongst his patients he numbered De Quincey and his family. De Quincey's eldest son died from a cerebral complaint, and the autopsy revealed an interesting pathological condition which formed the subject of Balfour's investigation, and an account of it his first published scientific paper.

From the claims of Medicine Balfour could wrest little time for botanical pursuits, but his holiday always meant the botanical exploration of some area, preferably alpine, and his home became a centre for men of kindred tastes. There in co-operation with his old teacher Graham, and with Greville, Forbes, Falconer, Parnell, Munby and others, was instituted in 1836 the Botanical Society of Edinburgh, with wide aims for the promotion of Botany--amongst them the creation of a botanical library and a herbarium. This has proved a signal service to science. It was the pegging out of a claim which has been made effective. The Society after a life--as with all such societies--of fluctuating periods of greater and lesser activity, flourishes still, and its library and herbarium, transferred to the Crown when the space demand of their bulk became urgent, have been the foundation for the large botanical library and herbarium now maintained and subsidised by Government in the Royal Botanic Garden.

Plants gradually drew Balfour away from patients and in 1840 he carried the divorce so far as to establish himself as a teacher of Botany in the Extra-mural Medical School in Edinburgh--that exemplar of free-trade in teaching--from which so many of the famous occupants of Chairs in the University have entered its portals. But only in 1842, when Sir William Hooker moved to Kew and a vacancy was then caused in the Glasgow Chair of Botany to which Balfour was elected, was he able to give up medical practice entirely.

In Glasgow the first years of Balfour's botanical career were spent, but they were few. On the death of Graham he returned to Edinburgh as Professor of Medicine and Botany and Keeper of the Royal Botanic Garden--the electors passing over Joseph Dalton Hooker also a candidate. In the sphere of these offices the rest of his active life was passed until his retirement in 1879. He came to the University of Edinburgh at a time when the reputation of its medical school was upheld by a remarkable band of teachers in the Medical Faculty--Allen Thomson, Alison, Christison, Goodsir, Gregory, Jameson, Simpson, Syme--and when the struggle of the University after a revised constitution was approaching the climax reached in 1858, when with other Scottish Universities Edinburgh obtained autonomy, and science was enfranchised. Of this Faculty he became Dean, and held office until close upon the time when he became Emeritus. In all the discussions and controversies, destructive and constructive, that attached to so weighty a crisis, Balfour's influence and outlook for science were used with effect, and no less influential were his action and advice in subsequent years when the specific question of medical reform was raised, as it so often was.

Absorbing administrative work of this kind, to which were soon added the duties of a Secretary of the Royal Society of Edinburgh--(and he remained in the Secretariat to the end of his active life)--as well as those of an editor of the _Edinburgh New Philosophical Journal_--(afterwards merged in the _Annals and Magazine of Natural History_)--of Secretary of the Royal Caledonian Horticultural Society and of other offices, made inroad alike upon time and energy of a man who had also the administration of the Royal Botanic Garden in his hands, as well as the calls of his Professorship of Botany to attend to. But Balfour was untiring in industry, prompt and precise in method, and administrative work appealed to him.

Though liable like his predecessors to undertake clinical medical teaching, Balfour, save for occasionally acting as _locum tenens_, took no share in it, and his energies in teaching were devoted to Botany. On the lines he followed he was pioneer. We have seen that Field Botany had been for several decades a characteristic of the Edinburgh Botanic School. Whilst maintaining this feature, Balfour added laboratory work. The word "laboratory" was not then in vogue, and "microscopical room" was the designation of the new domain in which the "guillotine," not the "microtome," was used. In the sphere of practical teaching this was a notable advance, and the more so when the technical difficulties that had to be overcome are remembered--the days of cheap microscopes were but beginning, aniline dyes were not yet. Nevertheless the student of the time had opportunity were he so minded of examining plant-form and plant-structure for himself under direction, and if the equipment for work were not so perfect mechanically as modern methods now permit of, the training in minute observation was no less excellent than that of to-day, and the educational effect of the teaching no less valuable. The scheme of work was that of the text-books--passing progressively from tissues to organs vegetative and reproductive both phanerogamic and cryptogamic. The specialisation of the type system had not come.

Before he was able to establish, as he did in the early fifties, practical laboratory classes, Balfour had introduced a system of demonstrations of microscopic objects and of physiological experiments in illustration daily of the subject of his lecture, and it is testimony to his power of infusing zeal in pupils that there was always a contingent of them ready to come to the Botanic Garden at six o'clock in the morning to give voluntary aid in the arranging of these demonstrations for the lecture at eight o'clock. Many of those who came have recorded that they found that period and its work one of the most inspiring in their student history.

This new departure in teaching did not interfere with the continuation and extension of field-work, which up to this time had been the form of practical study cultivated in Edinburgh. On the contrary the Botanical Excursion gave Balfour an outlet for energy and favourable opportunity for the exercise of those gifts of personal magnetism and intellectual stimulus through which he influenced and guided many generations of students. Every Saturday during the summer session an excursion was made, and one of some days' duration usually brought the session to a close. Through these excursions the greater part of Scotland was traversed--on one occasion the terminal excursion of the session was to Switzerland--and the features of flora and vegetation were brought to the attention of many hundreds of students.

The aim and result of the excursion were not solely the acquisition of plants and their identification. The stimulating effect on many of this side of Botany is evidenced even in our day by the zeal with which search after rare plants is pursued, and in the eagerness displayed in the race after micro-forms. But the enticement of acquisition and discovery of novelty whilst there were not the governing influences in Balfour's excursion. In touch as he was with the problems of organography in its fullest sense, a man of wide reading familiar with the botanical work of his time, and associated as he had been in the field with men like Edward Forbes and Hewett Cottrell Watson, Balfour could and did look at plants from the standpoint of their place in vegetation, and in relation to the conditions of growth, and as having a history in their habitat. His teaching reflected this. It was never classification, diagnosis, and nomenclature as the end-all of Botany. The details emphasised changed as the progress of botanical discovery gave new clues to explanation of form and relation, and it was the solvings and attempts at solvings of observed phenomena that gave that fascination to his excursions, the remembrance of which seems to have clung to those who had the fortune to join them. The succession of plants and plant-form from base to summit of a highland hill; contrasts of vegetation of stream-course, mountain pasture, alpine rock; high mountain forms of shore plants; intrusion and extirpation; factors of distribution and their influence;--those and other problems of what we now term Ecological Botany were themes on which the Professor discoursed in his rambles, filling the pupil with information and forcing him to think out to such conclusion as he might on the evidence before him. And then the whole occasion was so enlivened by the outgo of good humour and mirth in joke and pun and story, that fatigue and weariness, which the physical exercise might evoke in those less attuned than the wiry Professor, were drowned in the sunny current of humanity.

I mention this practical teaching first, for it was the characteristic feature, but the idea of practical illustration pervaded all Balfour's effort. His lecture table became a synopsis of the lecture--living plants, herbarium material, museum specimens, all were pressed into service to elucidate the points of the discourse, whilst the walls were tapestried by diagrams. Never did teacher more sedulously absorb the new for presentation to his pupils. He was a lucid expositor, and, apart from his University lectures, during many years was sought after for more popular discourses to non-academic audiences.

The period of Balfour's teaching included the momentous year 1860. The impulse of the new spirit introduced by Darwin did not stimulate Balfour as it might have done a younger man. His religious beliefs--always in evidence--were showing then the influence of his early environment, and whilst Darwin's work was incorporated in his teaching, the acceptance of Darwin's theory appeared too near the negation of faith. On Balfour indeed, as on others with like views, the immediate effect of the _Origin_ was the opposite of vivifying. It gave a shock. And this, I conceive, not so much a consequence of Darwin's own statement of his theory as of the forceful uncompromising attitude of the chief protagonist of his cause. Arrogance there was on the religious side, but no less also on the scientific side in the discussion. Perhaps it was well that the contest was sharp and bitter. It ended sooner, but its course was strewn with misconceptions and with confusion of cause and effect. In our days of complete reconciliation, when every tyro lisps in phyletic numbers as the outcome of Darwin's work, it is not amiss to recall the struggle at its inception--lest we forget.

The system of Essays which formed so important a part of Graham's teaching remained as prominent and was even developed further in Balfour's course in a way which had the inestimable merit of making the student feel that his study of plants had a living relationship with the everyday concerns of life. Thus when Simpson was engaged in his epoch-making investigations on anaesthetics, the subject for an essay was the effect of anaesthetics on sensitive plants, and by way of emphasis, the prize awarded was a gift by Simpson himself. Similarly Balfour enlisted the sympathy of Messrs Lawson, the prominent agricultural nurserymen of the day, and their prizes for dissection of grasses, for kinds of cereals, and like subjects, were constant reminders of the relations of botanical study to agriculture. The subjects of essays covered a wide field. The titles--influence of narcotic and irritant gases, changes which have taken place in the Flora of Britain during the historical era, cytogenesis and cell development, phanerogamous embryology, cryptogamous reproduction, teratology--may serve to indicate this, and an essential was always the practical illustration, microscopic or other.

For the use of the students Balfour compiled text-books which, like his lectures, are comprehensive in the field they cover, and encyclopaedic in the information they convey. His facile pen found expression too in numberless articles in encyclopaedias and magazines, and his activity as an expositor of botanical topics of the time was unbounded.

In the Botanic Garden Balfour obtained the material for the definite contributions he made to natural knowledge which are in the domain of Systematic Botany. No work in which Balfour engaged gave him more genuine pleasure than the administration of the Botanic Garden. Entering on the responsibility of its care when its repute was high, he left it on laying down office in even higher reputation, for in the McNabs--William and James--father and son--he had lieutenants of the first rank in gardening. During his regime the equipment for laboratory teaching to which reference has been made was installed, a museum to which old pupils all over the world contributed was instituted, and the Garden itself trebled in size, the latest addition, made just before his retirement, being an area to be cultivated as an arboretum for students of Forestry--a subject then beginning to claim attention.

With Balfour's retirement in 1879 the link of Botany with Medicine in the University was still further weakened. Medicine was left out of the title of the Chair to which Alexander Dickson succeeded.

Alexander Dickson of Hartree and Kilbucho was born at Edinburgh, 21st July, 1836. He was the second son of David Dickson of Hartree in Peeblesshire, and the representative of a family for long lairds of the estates of which, by the early death of his elder brother, he became proprietor. Educated privately, he entered the University of Edinburgh as a student of Medicine, graduating in 1860. Before graduation he had studied in Würzburg and in Berlin, particularly under Kölliker and Virchow, and after it he embarked on the stream of medical practice in Edinburgh. But that was convention--a demonstration of brass plate. His means placed him beyond the necessity of such professional work. His instinct lay in the direction of discovery of method more than in its application. During his student days he had shown a keen interest in Botany. Before graduation he had written on botanical subjects, and his thesis on graduation "The development of the flower in Caryophyllaceae" witnesses to his obsession. Whilst waiting for patients, he had continued work on embryogeny in plants, and when in 1862 the ill health of Professor Dickie at Aberdeen required the appointment of a substitute, the selection of Dickson set seal to his claims as a professed Botanist. In 1866 he succeeded Harvey as Professor in Dublin. Thence in 1868 he was translated to Glasgow as successor to Walker-Arnott, and in 1879 became Professor of Botany and Queen's Botanist in Edinburgh on the retirement of Balfour, and, holding these positions, he died in 1887.

Dickson's passion was not teaching, and his success is testimony to the quality of the man. He was adored by his students, as could not well be otherwise with a man of his geniality and kindliness; he took immense pains over his lectures, spending hours daily over the making of fresh drawings on the blackboard for his classes, holding that a student would copy a temporary sketch although he would not copy a permanent wall-diagram; the lecture itself was a model of scientific presentment; at excursions he was untiring in demonstration and in fruitful suggestion, and he was always ready to give of his best to his pupils; but his real love was for research and he carried out many organographical investigations which have added to the sum of natural knowledge. His record in published papers far exceeds that of any of his predecessors, and the quality of his work recalls that of Irmisch. Flower-morphology, embryogeny, teratology, were the subjects to which he gave most attention in research, and in them he obtained results of solid and permanent value. For a time the subject of phyllotaxy occupied him, but it is not a fruitful theme although it gave him opportunity for showing his power of clear analysis; much more interesting was his subsequent work on pitcher plants of kinds.

Dickson possessed great skill in manipulation, and was strikingly effective in the use of his pencil in artistic delineation of the objects of his investigation. Careful in his work he took endless pains to secure that accuracy which it always shows. Further, his subject is always illumined by the comparative method of treatment which his wide knowledge and sound critical faculty enabled him to bring to bear upon it.

The duties of his lairdship were no light ones to Dickson who had set himself to build up again what had come to him in an impoverished condition, and affairs of Church and State were a very real interest to him. Amidst all these ties, to which has to be added the administration of the Botanic Garden, in which during his tenure a new and enlarged Lecture Hall was built, he found time to cultivate the musical faculty for which he was distinguished; not only was he a pianist of mark, but he found absorbing zest in the collecting of national airs sung by the peasants of Scotland.

In the line of Professors of Botany in Edinburgh no one ranked higher in distinction than Alexander Dickson, with whose name I conclude this sketch.

FOOTNOTE:

[135] His portrait forms the frontispiece of this book.

SIR JOSEPH DALTON HOOKER

1817-1911

BY F. O. BOWER.

His long life--childhood and education--travels--Geological work--Morphological Memoirs--administrative duties--systematic works--relations with Darwin--acceptance of Mutability of Species--his philosophical Essays--their influence in advancing Evolutionary Belief.

It is a difficult task to condense within suitable limits an appreciation of so long and strenuous a life as that of Sir Joseph Hooker. Naturally with age the bodily strength waned, but the vivid mind remained unimpaired to the end. He even continued his detailed observations till very shortly before his death in December, 1911. The list of his published works extends from 1837 to 1911, a record hardly to be equalled in any walk of intellectual life.

Sir Joseph Hooker was born at Halesworth, in Suffolk, in 1817. His father, Sir William Hooker, brought him to Glasgow as a child of four years of age, when he entered on his duties as Professor of Botany in 1821. The Professor established himself in Woodside Crescent, conveniently near to the Botanic Garden, then but recently established, but developing under his hands with wonderful rapidity. Doubtless his little son was familiar with it and its contents from childhood. He grew up in an atmosphere surcharged with the very science he was to do so much to advance. His father's home was the scene of manifold activities. It housed a rapidly growing herbarium and museum. It was there that the drawings were made to illustrate that amazing stream of descriptive works which Sir William was then producing. New species must have been almost daily under examination, often as living specimens. Between the garden and the house the boy must have witnessed constantly, during the most receptive years of childhood, the working of an establishment that was at the time without its equal in this country, or probably in any other. The eye and the memory must have been trained almost unconsciously. A knowledge of plants would be acquired as a natural consequence of the surroundings, and without the effort entailed by study in later years. Few ever have known, or ever will know, plants as he did. Such knowledge comes only from growing up with them from earliest childhood.

Side by side with this almost unconscious education in Botany the ordinary curriculum of school and of college was pursued. There is no record of academic successes either at the High School, or at the University of Glasgow, beyond a prize "for the best Essay on the Brain and Nerves," in 1836. But the following year saw his first publication: for he described, while still a student, three new species of Mosses. It may be remarked that, like his father, his first writings related to the lower Plants. He never lost his interest in them, though in later years duty diverted him to the study of the Flowering Plants. An incident of his student period, which he himself relates, is, however, a more clear indication of the life that was to follow than any early publication of new species. He tells how an opportunity was given him of reading the proofs of Darwin's _Voyage of the Beagle_. "I was hurrying on my studies (that is for the final examination in Medicine) ... and so pressed for time was I that I used to sleep with the sheets of 'The Journal' under my pillow, that I might read them between waking and rising. They impressed me profoundly, whilst they stimulated me to enthusiasm in the desire to travel and observe." The opportunity came to him almost at once in the four years' voyage to the Antarctic. At the age of 22, having passed his examinations, and graduated as M.D., he was equipped at every necessary point for his duties as Assistant Surgeon and Botanist in the "Erebus," then about to start, along with the "Terror," on the famous voyage under the command of Sir James Clark Ross.

No attempt will here be made to give any consecutive biographical sketch of Sir Joseph Hooker. Several such have already appeared. The interest of the reader will be more readily engaged by indicating the various lines of activity in which he excelled. He was never a professional teacher, except for a short period of service as deputy for Graham in Edinburgh. There was a moment when he might have been Professor in Edinburgh, but it passed. He left no pupils, except in the sense that all botanists have learned from him through his books. We shall contemplate him rather as a Traveller and Geographer, as a Geologist, as a Morphologist, as an Administrator, as a Scientific Systematist, and above all as a Philosophical Biologist. He played each of these several parts in the Drama of Science. The endeavour will be made, however imperfectly, to touch upon them all.

The experiences of Hooker as a _traveller_ began immediately after taking his degree, with his commission in 1839 as Assistant Surgeon and Botanist in the "Erebus." Scientific Exploration was still in its heroic age. Darwin was only three years back from the voyage of the "Beagle." We may well hold the years from 1831, when the "Beagle" sailed, to 1851, when Hooker returned from his Indian journey, or 1852, when Wallace returned from the Amazon, to have been its golden period. Certainly it was if we measure by results. Unmatched opportunity for travel in remote and unknown lands was then combined with unmatched capacity of those who engaged in it. Nor was this a mere matter of chance. For Darwin, Wallace, and Hooker all seized, if they did not in some measure make, their opportunity.

The intrepid Ross, with his two sailing ships, the "Erebus" and the "Terror," probed at suitable seasons during four years the extreme south. The very names of the Great Ice Barrier, M'Murdo Sound, Mount Erebus and Mount Terror, made familiar to us by adventures seventy years later under steam, remain to mark some of his additions to the map of the world. Young Hooker took his full share of risks, up to the point of being peremptorily ordered back on one occasion by his commanding officer. To his activity and willingness, combined with an opportunity that can never recur in the same form, is due that great collection of specimens, and that wide body of fact which he acquired. On the outward and return voyages, or in the intervals when the season was not favourable for entering the extreme southern seas, the expedition visited Ascension, St Helena, the Cape, New Zealand, Australia, Tasmania, Kerguelen Island, Tierra del Fuego, and the Falkland Islands. The prime object of the voyage was a magnetic survey, and this determined its course. But it brought this secondary consequence; that Hooker had the chance of observing and collecting upon all the great circumpolar areas of the southern hemisphere. The results he later welded together into his first great work, _The Antarctic Flora_.

Very soon after his return from the Antarctic the craving for travel broke out afresh in him. He longed to see a tropical Flora in a mountainous country, and to compare it at different levels with that of temperate and arctic zones. Two alternatives arose before him: the Andes and the Himalaya. He chose the latter, being influenced by promises of assistance from Dr Falconer, the Superintendent of the Calcutta Garden. But before he left England his journey came under the recognition of Government. He not only received grants on the condition that the collections made should be located in the Herbarium at Kew, but he was accredited by the Indian Government to the Rulers, and the British Residents, in the countries whose hitherto untrodden ways he was to explore. After passing the cold season of 1848 in making himself acquainted with the vegetation of the plains and hills of Western Bengal, he struck north to the Sikkim Himalaya. Hither he had been directed by Lord Auckland and by Dr Falconer, as to ground unbroken by traveller or naturalist. The story of this remarkable journey, its results and its vicissitudes, including the forcible detention of himself and his companion Dr Campbell by a faction of the Court of Sikkim, is to be found in his _Himalayan Journals_. These most fascinating volumes of travel were published in 1854. They tell how he spent two years in the botanical exploration and topographical survey of the state of Sikkim, and of a number of the passes leading into Thibet; and how towards the close of 1848 he even crossed the western frontier of Sikkim, and explored a portion of Nepal that has never since been open to travellers. In 1849 he returned to Darjeeling, and busied himself with arranging his vast collections. Here he was joined by an old fellow-student of Glasgow, Dr Thomas Thomson, son of the professor of that name. The two friends spent the year 1850 in the botanical investigation of Eastern Bengal, Chittagong, Silhet, and the Khasia hills. In 1851 they returned together to England.

The botanical results of these Indian journeys were immense, and they provided the material for much of Hooker's later scientific writing. Nearly 7000 species of Indian plants were collected by these two Glasgow graduates. But Hooker was not a mere specialist. His _Journals_ are full of other observations, ethnographical, ornithological, and entomological. His topographical results especially were of the highest importance. They formed the basis of a map published by the Indian Topographical Survey. By the aid of it the operations of various campaigns and political missions have since been carried to a successful issue. If he were not known as a Botanist, he would still have his assured place as a Geographer.

After his return from India, nine years ensued of quiet work at home. But in 1860 Hooker took part in a scientific visit to Syria and Palestine, ascending Mount Lebanon, where he specially paid attention to the decadent condition of the Cedars, his observations leading later to a general discussion of the genus. Again a period of ten years intervened, his next objective being Morocco. In 1871, with Mr Ball and Mr Maw, he penetrated the Atlas Range, never before examined botanically. His last great journey was in 1877, when he was sixty years of age. With his old friend, Prof. Asa Gray of Harvard, he visited Colorado, Wyoming, Utah, the Rocky Mountains, the Sierra Nevada, and California. Prof. Coulter of Chicago, who was one of the party in the Rockies, has told me how difficult it was to round up the two elderly enthusiasts to camp at night.

This is an extraordinary record of travel, especially so when we remember that all the journeys were fitted into the intervals of an otherwise busy life of scientific work and administration. At one time or another he had touched upon every great continental area of the earth's surface. Many isolated islands had also been examined by him, especially on the Antarctic voyage. Not only were fresh regions thus opened up for survey and collection, but each objective of the later journeys was definitely chosen for scientific reasons. Each expedition helped to suggest or to solve major problems. Such problems related not only to the distribution, but also to the very origin of species. Darwin saw this with unerring judgment as early as 1845. Hooker was then but twenty-eight years old, and the records of the Antarctic voyage were only in preparation. Nevertheless Darwin wrote with full assurance in a letter to Hooker himself: "I know I shall live to see you the first authority in Europe on that grand subject, that almost keystone of the laws of Creation, Geographical Distribution." Never was a forecast more fully justified. But that position, which Hooker undoubtedly had, could only have been attained through his personal experience as a traveller. Observation at first hand was the foundation upon which he chiefly worked. Hooker the traveller prepared the way for Hooker the philosopher.

Sir Joseph Hooker would probably have declined to consider himself as a _Geologist_. He was, however, for some eighteen months official Botanist to the Geological Survey of Great Britain. He was appointed in April 1846, but relinquished the post in November 1847 in order to start on his Himalayan journey. During that short period three Memoirs were published by him on Plants of the Coal Period. They embodied results derived from the microscopic examination of plant-tissues preserved in Coal Balls, a study then newly introduced by Witham, and advanced by Mr Binney. It has since been greatly developed in this country. Such studies were continued by him at intervals up to 1855. While he was thus among the first to engage in this branch of enquiry, he may be said to have originated another line of study, since largely pursued by geologists. For he examined samples of diatomaceous ooze from the ocean-floor of the Antarctic, and so initiated the systematic treatment of the organic deposits of the deep sea. Yet another branch of geological enquiry was advanced by him in the Himalaya. For there he made observations on the glaciers of that great mountain chain, his notes supplying valuable material to both Lyell and Darwin. He also accumulated valuable data concerning the stupendous effects of sub-aerial denudation at great elevations. His latest contribution of a geological character was in 1889, when he returned to an old problem of his youth, the Silurian fossil _Pachytheca_. But he had to leave the question of its nature still unsolved. This geological record is not an extensive one. But the quality and rapidity of the work showed that it was the time and opportunity and not the faculties that were wanting. Moreover, it is worthy of remark that the problems he handled were all nascent at the time he worked upon them.

The list of Sir Joseph Hooker's memoirs which deal _morphologically_ with more limited subjects than is possible in floristic works, is a restricted one. In 1856 he produced a monograph on the Balanophoraceae, based upon collections of material from the most varied sources. It is still an authority very widely quoted on these strange parasites. In 1859 he described the development and structure of the Pitchers of _Nepenthes_, while the physiological significance of these, and other organs of carnivorous plants, formed the subject of an Address before the British Association at Belfast, in 1874. And in 1863 his great monograph appeared upon that most remarkable of all Gymnospermic plants, _Welwitschia_. These works bore the character of a later period than the time when they were produced. In Britain, between 1840 and 1875, investigation in the laboratory, by microscopic analysis of tissues, was almost throttled by the overwhelming success of systematic and descriptive work. The revival of investigation in the laboratory rather than that in the herbarium dates from about 1875. But we see that Hooker was one of the few who, prior to that revival, pursued careful microscopic analysis side by side with systematic and floristic work.

The noble establishment of the Royal Gardens at Kew is often spoken of as the Mecca of Botanists. It is also the Paradise of the populace of London. It was the Hookers, father and son, who made Kew what it is. When we contemplate Sir Joseph as an _administrator_, we immediately think of the great establishment which he and his father ruled during the first half century of its history as a public institution. Kew had existed for long as a Royal Appanage before it was handed over to the Nation. The Botanic Garden had, indeed, ranked for upwards of half a century as the richest in the world. But after the death of King George III. it had retrograded scientifically. On the accession of Queen Victoria a revision of the Royal Household had become necessary. It was then decided to transfer the garden to the Commissioners of Woods and Forests. This took place in 1840, and in 1841 Sir William Hooker, who was then Professor in Glasgow, was appointed the first Director. The move to Kew, whither he took his private Library, Herbarium, and Museum, was carried out in the absence of his son, who was still in the Antarctic. It was not till the Himalayan journey was over in 1851 that Sir Joseph settled at Kew, his great collections having already been consigned there by agreement with the Government. In 1855 he was appointed assistant to his father in the Directorship. Finally, he became himself Director on his father's death in 1865, and he held the position for twenty years.

So long associated together, it is difficult to disentangle the parts that father and son actually played in the creation of Kew as it now is. Nor is there need to attempt it. The original area of the Garden at Kew was less than 20 acres. But in 1855, when Sir Joseph joined his father in the directorate, it had grown by successive additions to 70 acres. Finally, the large area of 650 acres came under the Director's control. Numerous large glass houses were built. Three Museums were established, and the vast Herbarium and Library founded and developed. The Garden Staff rose to more than 100 men. The day-by-day administration of such an establishment would necessarily make great demands upon the time, energy, tact, and skill of its official head. But in addition there was the growing correspondence to be attended to, on the one hand with botanists all over the world, on the other with the Government Departments, and especially with the Indian and Colonial Offices. As the activity of the Garden extended, there grew up a large staff of scientific experts and artists, whose duties centred round the Herbarium and Library. These all looked to the Director for their guidance and control. The descriptive work prepared by them for publication took formidable dimensions. The production of the Floras of India, and of the Colonies, the publication of which was conducted under Government subvention, had to be organised and carried through. These matters are mentioned here so as to give some idea of the extent and complexity of the work which was being carried on at Kew. For ten years as Assistant Director, and for twenty years as Director, Sir Joseph Hooker guided this complex machine. The efficiency of his rule was shown by the increasing estimation in which the Garden was held by all who were able to judge.

It was the founding of the Herbarium and Library at Kew which, more than anything else, strengthened the scientific establishment. As taken over from the Crown the Garden possessed neither. But Sir William brought with him from Glasgow his own collections, already the most extensive in private hands. For long years after coming to Kew he maintained and added to his store at his own expense. But finally his collections were acquired after his death by Government. His Herbarium was merged with the fine Herbarium of Bentham, already presented to the nation in 1857. Thus, the opening years of Sir Joseph's directorate saw the organisation upon a public basis of that magnificent Herbarium and Library, which now contains not only his father's collections, but also his own. Among the enormous additions since made to the Herbarium of Kew, its greatest interest will always be centred in the Hookerian collections which it contains.

It might be thought that such drafts as these upon the time and energies of a scientific man would leave no opportunity for other duties. But it was while burdened with the directorship that Sir Joseph was called to the highest administrative office in science in Great Britain. He served as President of the Royal Society from 1873 to 1878. The obligations of that position are far from being limited to the requirements of the Society itself. The Government of the day has always been in the habit of taking its president and officials into consultation in scientific matters of public importance. In these years the administrative demands upon Sir Joseph were the greatest of his life. They are marked by a temporary pause in the stream of publication. None of his own larger works belong to this period. It happens only too often in this country that our ablest men are thus paralysed in their scientific careers by the potent vortex of administration. Not a few succumb, and cease altogether to produce. They are caught as in the eddy of the Lorelei, and are so hopelessly entangled that they never emerge again. They fail to realise, or realise too late, that the administration of matters relating to a science is not an end in itself, but only a means to an end. Some, the steadfast and invincible seekers after truth, though held by the eddy for a time, pass again into the main stream. Hooker was one of these. The Presidency of the Royal Society ended at the usual term of five years. Seven years later he demitted office as Director of Kew. He was thus free in 1885, still a young man in vigour though not in years. For over a quarter of a century after retirement he devoted the energy of his old age to peculiarly fruitful scientific work. Thus the administrative tie upon him was only temporary. So long as it lasted he faithfully obeyed the call of duty, notwithstanding the restrictions it imposed.

No exhaustive catalogue need be given of the works upon which the reputation of Sir Joseph Hooker as a _scientific systematist_ was founded. It must suffice briefly to consider his four greatest systematic works, _The Antarctic Flora_, _The Flora of British India_, _The Genera Plantarum_, and the _Index Kewensis_.

We have seen how on the Antarctic voyage Hooker had the opportunity of collecting on all the great circumpolar areas of the Southern Hemisphere. His _Antarctic Flora_ was based on the collections and observations then made. It was published in six large quarto volumes. The first related to the Lord Auckland and Campbell Islands (1843-1845); the second to Fuegia and the Falkland Islands (1845-1847); the third and fourth to New Zealand (1851-1853); and the fifth and sixth to Tasmania (1853-1860). They describe about 3000 species, while on 530 plates 1095 species are depicted, usually with detailed analytical drawings. But these volumes did not merely contain reports of explorations, or descriptions of the many new species collected. There is much more than this in them. All the known facts that could be gathered were incorporated, so that they became systematically elaborated and complete Floras of the several countries. Moreover, in the last of them, the _Flora Tasmaniae_, there is an Introductory Essay, which in itself would have made Hooker famous. We shall return to this later. Meanwhile we recognise that the publication of the _Botanical Results of Ross's Voyage_ established Hooker's reputation as a Traveller and Botanist of the first rank.

What he did for the Antarctic in his youth he continued in mature life for British India. While the publication of the _Antarctic Flora_ was still in progress, he made his Indian journeys. The vast collections amassed by himself and Dr Thomson were consigned by agreement with Government to Kew. Thither had also been brought in 1858 "seven waggon-loads of collections from the cellars of the India House in Leadenhall Street, where they had been accumulating for many years." They included the herbaria of Falconer and Griffith. Such materials, with other large additions made from time to time, flowed into the already rich Herbarium at Kew. This was the material upon which Sir Joseph Hooker was to base his _Magnum Opus_, the _Flora of British India_.

Already in 1855 Sir Joseph, with his Glasgow college friend, Thomas Thomson, had essayed to prepare a "Flora Indica." It never advanced beyond its first volume. But if it had been completed on the scale set by that volume, it would have reached nearly 12,000 pages! After a pause of over fifteen years Hooker made a fresh start, aided now by a staff of collaborators, and the _Flora of British India_ was the result. It was conceived, he says with regret, upon a restricted plan. Nevertheless it ran to seven volumes, published between the years 1872 and 1897. There are nearly 6000 pages of letterpress, relating to 16,000 species. It is, he says in the Preface, a pioneer work, and necessarily incomplete. But he hopes it may "help the phytographer to discuss problems of distribution of plants from the point of view of what is perhaps the richest, and is certainly the most varied botanical area on the surface of the globe."

Scarcely was this great work ended when Dr Trimen died. He left the _Ceylon Flora_, on which he had been engaged, incomplete. Three volumes were already published, but the fourth was far from finished, and the fifth hardly touched. The Ceylon Government applied to Hooker, and though he was now eighty years of age, he responded to the call. The completing volumes were issued in 1898 and 1900. This was no mere raking over afresh the materials worked already into the _Indian Flora_. For Ceylon includes a strong Malayan element in its vegetation. It has, moreover, a very large number of endemic species, and even genera. This last floristic work of Sir Joseph may be held fitly to round off his treatment of the Indian Peninsula. His last contribution to its botany was in the form of a "Sketch of the Vegetation of the Indian Empire," including Ceylon, Burma, and the Malay Peninsula. It was written for the _Imperial Gazetteer_, at the request of the Government of India. No one could have been so well qualified for this as the veteran who had spent more than half a century in preparation for it. It was published in 1904, and forms the natural close to the most remarkable study of a vast and varied Flora that has ever been carried through by one ruling mind.

The third of the systematic works selected for our consideration is the _Genera Plantarum_. It was produced in collaboration with Mr Bentham. Of its three massive volumes the first was published in 1865, and the work was completed in 1883. It consists of a codification of the Latin diagnoses of all the genera of Flowering Plants. It is essentially a work for the technical botanist, but for him it is indispensable. Of the known species of plants many show such close similarity of their characters that their kinship is recognised by grouping them into genera. In order that these genera may be accurately defined it is necessary to have a _précis_ of the characters which their species have in common. This must be so drawn that it shall also serve for purposes of diagnosis from allied genera. Such drafting requires not only a keen appreciation of fact, but also the verbal clearness and accuracy of the conveyancing barrister. The facts could only be obtained by access to a reliable and rich Herbarium. Bentham and Hooker, working together at Kew, satisfied these drastic requirements more fully than any botanists of their time. The only real predecessors of this monumental work were the _Genera Plantarum_ of Linnaeus (1737-1764) and of Jussieu (1789), to which may be added that of Endlicher (1836-1840). But all of these were written while the number of known genera and species was smaller. The difficulty of the task of Bentham and Hooker was greatly enhanced by their wider knowledge. But their _Genera Plantarum_ is on that account a nearer approach to finality. Hitherto its supremacy has not been challenged.

The fourth of the great systematic works of Hooker mentioned above was the _Index Kewensis_. It was produced upon the plan and under the supervision of Sir Joseph by Dr Daydon Jackson and a staff of clerks. The publication began in 1893, and successive supplements to its four quarto volumes are still appearing at intervals. The expense was borne by Charles Darwin. The scheme originated in the difficulty he had found in the accurate naming of plants. For "synonyms" have frequently been given by different writers to the same species, and this had led to endless confusion. The object of the _Index_ was to provide an authoritative list of all the names that have been used, with reference to the author of each and to its place of publication. The habitat of the plant was also to be given. The correct name in use according to certain well-recognised rules of nomenclature was to be indicated by type different from that of the synonyms superseded by it. The only predecessor of such an Index was Steudel's _Nomenclator Botanicus_, a book greatly prized by Darwin, though long out of date. He wished at first to produce a modern edition of Steudel's _Nomenclator_. This idea was, however, amended, and it was resolved to construct a new list of genera and species, founded upon Bentham and Hooker's _Genera Plantarum_. Sir Joseph Hooker was asked by Mr Darwin to take into consideration the extent and scope of the proposed work, and to suggest the best means of having it executed. He undertook the task, and it was he who laid out the lines to be followed. After years of labour by Dr Daydon Jackson and his staff, the work was produced. But Sir Joseph read and narrowly criticised all the proofs. Imagine four large quarto volumes, containing in the aggregate 2500 pages, each page bearing three columns of close print, and each column about fifty names. The total figures out to about 375,000 specific names, all of which were critically considered by the octogenarian editor! Surely no greater technical benefit was ever conferred upon a future generation by the veterans of science than this _Index_. It smooths the way for every systematist who comes after. It stands as a monument to an intimate friendship. It bears witness to the munificence of Darwin, and the ungrudging personal care of Hooker.

But the author of great works such as these was still willing to help those of less ambitious flights. I must not omit to mention two books which, being more modest in their scope, have reached the hands of many in this country. In 1870 Hooker produced his _Students' Flora of the British Islands_, of which later editions appeared in 1878 and 1884. It was published in order to "supply students and field botanists with a fuller account of the plants of the British Isles than the manuals hitherto in use aim at giving." In 1887 he edited, after the death of its author, the fifth edition of Bentham's _Handbook of the British Flora_. Both of these still hold the field, though they require to be brought up to date in point of classification and nomenclature.

The object of these brief sketches of four of the great systematic works of Sir Joseph Hooker has been to show how fully he was imbued with the old systematic methods: how he advanced, improved and extended them, and was in his time their chief exponent. His father had held a similar position in the generation before him. But the elder Hooker, true to his generation, treated his species as fixed and immutable. He did not generalise from them. His end was attained by their accurate recognition, delineation, description, and classification. The younger Hooker, while in this work he was not a whit behind the best of his predecessors, saw further than they. He was not satisfied with the mere record of species as they were. He sought to penetrate the mystery of the origin of species. In fact, he was not merely a Scientific Systematist in the older sense. He was a _Philosophical Biologist_ in the new and nascent sense of the middle period of the nineteenth century. He was an almost life-long friend of Charles Darwin. He was the first confidant of his species theory, and, excepting Wallace, its first whole-hearted adherent. But he was also Darwin's constant and welcome adviser and critic. Well indeed was it for the successful launch of evolutionary theory that old-fashioned systematists took it in hand. Both Darwin and Hooker had wide and detailed knowledge of species as the starting-point of their induction.

Before we trace the part which Hooker himself played in the drama of evolutionary theory, it will be well to glance at his personal relations with Darwin himself. It has been seen how he read the proof-sheets of the _Voyage of the 'Beagle'_ while still in his last year of medical study. But before he started for the Antarctic he was introduced to its author. It was in Trafalgar Square, and the interview was brief but cordial. On returning from the Antarctic, correspondence was opened in 1843. In January 1844 Hooker received the memorable letter confiding to him the germ of the Theory of Descent. Darwin wrote thus: "At last gleams of light have come, and I am almost convinced that species are not (it is like confessing a murder) immutable:--I think I have found (here's presumption!) the simple way by which species become exquisitely adapted to various ends." This was probably the first communication by Darwin of his species-theory to any scientific colleague.

The correspondence thus happily initiated between Darwin and Hooker is preserved in the _Life and Letters of Charles Darwin_, and in the two volumes of _Letters_ subsequently published. They show on the one hand the rapid growth of a deep friendship between these two potent minds, which ended only beside the grave of Darwin in Westminster Abbey. But what is more important is that these letters reveal, in a way that none of the published work of either could have done, the steps in the growth of the great generalisation. We read of the doubts of one or the other; the gradual accumulation of material facts; the criticisms and amendments in face of new evidence; and the slow progress from tentative hypothesis to assured belief. We ourselves have grown up since the clash of opinion for and against the mutability of species died down. It is hard for us to understand the strength of the feelings aroused: the bitterness of the attack by the opponents of the theory, and the fortitude demanded from its adherents. It is best to obtain evidence on such matters at first hand; and this is what is supplied by the correspondence between Darwin and Hooker.

How complete the understanding between the friends soon became is shown by the provisions made by Darwin for the publication of his manuscripts in case of sudden death. He wrote in August 1854 the definite direction "Hooker by far the best man to edit my species volume": and this notwithstanding that he writes to him as a "stern and awful judge and sceptic." But again, in a letter a few months later, he says to him: "I forgot at the moment that you are the one living soul from whom I have constantly received sympathy." I have already said that Hooker was not only Darwin's first confidant but also the first to accept his theory of mutability of species. But even he did not fully assent to it till after its first publication. The latter point comes out clearly from the letters. In January 1859, six months after the reading of their joint communications to the Linnean Society, Darwin writes to Wallace: "You ask about Lyell's frame of mind. I think he is somewhat staggered, but does not give in ... I think he will end by being perverted. Dr Hooker has become almost as heterodox as you or I, and I look at Hooker as by far the most capable judge in Europe." In September 1859 Darwin writes to W. D. Fox: "Lyell has read about half of the volume in clean sheets ... He is wavering so much about the immutability of species that I expect he will come round. Hooker has come round, and will publish his belief soon." In the following month, writing to Hooker, Darwin says: "I have spoken of you here as a convert made by me: but I know well how much larger the share has been of your own self-thought." A letter to Wallace of November 1859 bears this postscript: "I think that I told you before that Hooker is a complete convert. If I can convert Huxley I shall be content." And lastly, in a letter to W. B. Carpenter, of the same month, Darwin says: "As yet I know only one believer, but I look at him as of the greatest authority, viz. Hooker." These quotations clearly show that, while Lyell wavered, and Huxley had not yet come in, Hooker was a complete adherent in 1859 to the doctrine of the mutability of species. Excepting Wallace, he was the first, in fact, of the great group that stood round Darwin, as he was the last of them to survive.

The story of the joint communication of Darwin and of Wallace to the Linnean Society "On the tendency of Species to form Varieties, and on the Perpetuation of Varieties and Species by Natural Means of Selection" will be fresh in the minds of readers, for the fiftieth anniversary of the event was lately celebrated in London. It was Sir Charles Lyell and Sir Joseph Hooker who jointly communicated the two papers to the society, together with the evidence of the priority of Darwin in the enquiry. Nothing could then have been more apposite than the personal history which Sir Joseph gave at the Darwin-Wallace celebration, held by the Linnean Society in 1908. He then told, at first hand, the exact circumstances under which the joint papers were produced. Nor could the expressions used by the President (Dr Scott) when thanking Sir Joseph, and presenting to him the Darwin-Wallace Medal, have been improved. He said: "The incalculable benefit that your constant friendship, advice, and alliance were to Mr Darwin himself, is summed up in his own words, used in 1864: 'You have represented for many years the whole great public to me.'" The President then added: "Of all men living it is to you more than to any other that the great generalisation of Darwin and Wallace owes its triumph."

The very last appearance of Hooker at any large public gathering of biologists was at the centenary of Darwin's birth, celebrated at Cambridge, in 1909. None who were there will forget the tall figure of the veteran, aged, but still vigorous, with vivacity in every feature. How gladly he accepted the congratulations of his many friends, and how heartily he rejoiced over the full acceptance of the theory he had himself done so much to promote. The end came only two years later, in December last. Many will have wished that the great group of the protagonists of Evolution, Darwin, Lyell, and Hooker, should have found their final resting-place together in Westminster Abbey. But this was not to be. Personal and family ties held him closer to Kew. And he lies there in classic ground beside his father.

Having thus sketched the intimate relations which subsisted between Hooker and Darwin, it remains to appraise his own positive contributions to _Philosophical Biology_. He himself, in his Address as President of the British Association at Norwich in 1868, gives an insight into his early attitude in the enquiry into biological questions. "Having myself," he says, "been a student of Moral Philosophy in a Northern University, I entered on my scientific career full of hopes that Metaphysics would prove a useful mentor, if not a guide in science. I soon found, however, that it availed me nothing, and I long ago arrived at the conclusion so well put by Agassiz, when he says, 'We trust that the time is not distant when it will be universally understood that the battle of the evidences will have to be fought on the field of Physical Science, and not on that of the Metaphysical.'" This was the difficult lesson of the period when Evolution was born. Hooker learned the lesson early. He cleared his mental outlook from all preconceptions, and worked down to the bed-rock of objective fact. Thus he was free to use his vast and detailed knowledge in advancing, along the lines of induction alone, towards sound generalisations. These had their very close relation to questions of the mutability of species. The subject was approached by him through the study of geographical distribution, in which, as we have seen, he had at an early age become the leading authority.

The fame of Sir Joseph Hooker as a Philosophical Biologist rests upon a masterly series of Essays and Addresses. The chief of these were The Introductory Essay to the _Flora Tasmaniae_, dealing with the Antarctic Flora as a whole; The Essay on the Distribution of Arctic Plants, published in 1862; The Discourse on Insular Floras in 1866; The Presidential Address to the British Association at Norwich in 1868; his Address at York, in 1881, on Geographical Distribution; and finally, The Essay on the Vegetation of India, published in 1904. None of these were mere inspirations of the moment. They were the outcome of arduous journeys to observe and to collect, and subsequently of careful analysis of the specimens and of the facts. The dates of publication bear this out. The Essay on the Antarctic Flora appeared about twenty years after the completion of the voyage. The Essay on the Vegetation of India was not published till more than half a century after Hooker first set foot in India. It is upon such foundations that Hooker's reputation as a great constructive thinker is securely based.

The first-named of these essays will probably be estimated as the most notable of them all in the History of Science. It was completed in November 1859, barely a year after the joint communications of Darwin and Wallace to the Linnean Society, and before the _Origin of Species_ had appeared. It was to this Essay that Darwin referred when he wrote that "Hooker has come round, and will publish his belief soon." But this publication of his belief was not merely an echo of assent to Darwin's own opinions. It was a reasoned statement, advanced upon the basis of his "own self-thought," and his own wide systematic and geographical experience. From these sources he drew for himself support for the "hypothesis that species are derivative, and mutable." He points out how the natural history of Australia seemed specially suited to test such a theory, on account of the comparative uniformity of the physical features being accompanied by a great variety in its Flora, and the peculiarity of both its Fauna and Flora, as compared with other countries. After the test had been made, on the basis of study of some 8000 species, their characters, their spread, and their relations to those of other lands, he concludes decisively in favour of mutability and a doctrine of progression.

How highly this Essay was esteemed by his contemporaries is shown by the expressions of Lyell and of Darwin. The former writes: "I have just finished the reading of your splendid Essay on the Origin of Species, as illustrated by your wide botanical experience, and think it goes far to raise the variety-making hypothesis to the rank of a theory, as accounting for the manner in which new species enter the world." Darwin wrote: "I have finished your Essay. To my judgment it is by far the grandest and most interesting essay on subjects of the nature discussed I have ever read."

But besides its historical interest in relation to the Species Question, the Essay contained what was up to its time the most scientific treatment of a large area from the point of view of the Plant-Geographer. He found that the Antarctic, like the Arctic Flora, is very uniform round the Globe. The same species in many cases occur on every island, though thousands of miles of ocean may intervene. Many of these species reappear on the mountains of Southern Chili, Australia, Tasmania, and New Zealand. The Southern Temperate Floras, on the other hand, of South America, South Africa, Australia, and New Zealand differ more among themselves than do the Floras of Europe, Northern Asia, and North America. To explain these facts he suggested the probable former existence, during a warmer period than the present, of a centre of creation of new species in the Southern Ocean, in the form of either a continent or an archipelago, from which the Antarctic Flora radiated. This hypothesis has since been held open to doubt. But the fact that it was suggested shows the broad view which he was prepared to take of the problem before him. His method was essentially that which is now styled "Ecological." Many hold this to be a new phase of botanical enquiry, introduced by Professor Warming in 1895. No one will deny the value of the increased precision which he then brought into such studies. But in point of fact it was Ecology on the grand scale that Sir Joseph Hooker practised in the Antarctic in 1840. Moreover it was pursued, not in regions of old civilisation, but in lands where Nature held her sway untouched by the hand of man.

This Essay on the Flora of the Antarctic was the prototype of the great series. Sir Joseph examined the Arctic Flora from similar points of view. He explained the circumpolar uniformity which it shows, and the prevalence of Scandinavian types, together with the peculiarly limited nature of the Flora of the southward peninsula of Greenland. He extended his enquiries to oceanic islands. He pointed out that the conditions which dictated circumpolar distribution are absent from them; but that other conditions exist in them which account for the strange features which their vegetation shows. He extended the application of such methods to the Himalaya and to Central Asia. He joined with Asa Gray in like enquiries in North America. The latter had already given a scientific explanation of the surprising fact that the plants of the Eastern States resemble more nearly those of China than do those of the Pacific Slope. In resolving these and other problems it was not only the vegetation itself that was studied. The changes of climate in geological time, and of the earth's crust as demonstrated by geologists, formed part of the basis on which he worked. For it is facts such as these which have determined the migration of Floras. And migration, as well as mutability of species, entered into most of his speculations. The Essays of this magnificent series are like pictures painted with a full brush. The boldness and mastery which they show sprang from long discipline and wide experience.

Finally, the chief results of the Phyto-Geographical work of himself and of others were summed up in the great Address on "Geographical Distribution" at York. The Jubilee of the British Association was held there in 1881. It had been decided that each section should be presided over by a past President of the Association, and he had occupied that position at Norwich in 1868. Accordingly at York Hooker was appointed President of the Geographical Section, and he chose as the subject of his Address "The Geographical Distribution of Organic Beings." To him it illustrated "the interdependence of those Sciences which the Geographer should study." It is not enough merely to observe the topography of organisms, but their hypsometrical distribution must also be noted. Further, the changes of area and of altitude in exposed land-surfaces of which geology gives evidence, are essential features in the problem, together with the changes of climate, such as have determined the advance and retrocession of glacial conditions. Having noted these factors, he continued thus: "With the establishment of the doctrine of orderly evolution of species under known laws I close this list of those recognised principles of the science of geographical distribution, which must guide all who enter upon its pursuit. As Humboldt was its founder, and Forbes its reformer, so we must regard Darwin as its latest and greatest law-giver." Now, after thirty years, may we not add to these words of his, that Hooker was himself its greatest exponent?

And so we have followed, however inadequately, this great man into the various lines of scientific activity which he pursued. We have seen him to excel in them all. The cumulative result is that he is universally held to have been, during several decades, the most distinguished botanist of his time. He was before all things a philosopher. In him we see the foremost student of the broader aspects of Plant-Life at the time when evolutionary belief was nascent. His influence at that stirring period, though quiet, was far-reaching and deep. His work was both critical and constructive. His wide knowledge, his keen insight, his fearless judgment were invaluable in advancing that intellectual revolution which found its pivot in the mutability of species. The share he took in promoting it was second only to that of his life-long friend Charles Darwin.

INDEX

Absorption, Aristotelian views on, 68

---- Grew and, 58

---- Hales and, 73-76

---- Mariotte and, 68

Adanson, Plant families and, 41

Agassiz, appreciation of, 215, 319

Agriculture, investigations in, 234, 236-237

---- physiology and, 7

---- Theophrastus and, 9

Algae, Berkeley on British, 226

---- collection of, 214, 216

---- Harvey on, 208, 210-212, 216

---- systematic work on, 202

---- Williamson and, 252

Algal floras, 219

Alston, Charles, King's Botanist, =283-284=

---- Hales and, 285-286

---- investigations of, 285

---- publications of, 286

Alternation of generations, 188-189, 198

Amman, Morison's method and, 26

_Anabena_ filaments, Griffith on, 190, 196

Anatomical method, W. Hooker and, 147-148

Anatomy, Balfour and comparative, 262

---- Founders of, 2, 6, 44, 63, 67

---- Grew and plant, 47-57

---- Henfrey and Monocotyledon, 199

---- Hill and plant, 93, 94, 95

Annals of Botany, Ward and, 266

Annual rings, J. Hill and, 94

Antarctic flora, J. D. Hooker and, 305, 311-312

Anthrax, Ward on, 272

Apical growth, Nägeli and Leitgeb on, 135

Apogamy, Alston and, 286

Aquatic fungi, Ward on, 265

Aquatic _Myxomycete_, Ward and, 265

Arber, Agnes, on Grew, 44-64

Arber, Newell, on _Primofilices_, 257

Arboretum, founding of Edinburgh, 300

Archaeology, Williamson and, 249

Archegonia, discovery in Ferns of, 196-198

Aristotle, botanical writings of, 8

Aristotle, value of work of, 15

---- physiology and, 68

Ascent of sap, Grew's explanation of, 58

_Asclepiadaceae_, R. Brown on the, 114-116

Assimilation, Hales on, 80

Bacteria, action of light on, 273

Bacteriology, Ward on, 265, 271-273

Baker, J. Hill's quarrels with, 89-91

---- _Synopsis Filicum_ and, 146

_Balanophoraceae_, Griffith on the, 186

---- J. D. Hooker and the, 308

Balfour, Andrew, pioneer work of, 281

Balfour, J. Bayley, on the Edinburgh Professors, 280-301

---- ---- on the Ginger-beer plant, 269

Balfour, John Hutton, life of, =293-300=

---- ---- Edinburgh Professorship and, 293-295

---- ---- at Glasgow, 295

---- ---- administrative work of, 295

---- ---- teaching methods of, 299

Banks, Sir Joseph, W. Hooker and, 129

---- ---- R. Brown and, 110-111

---- ---- on "rust" disease, 275

Banksian collections, R. Brown and, 112-123, 134

de Bary, on potato disease, 266

---- on "rust" disease, 27

---- Ward's visit to, 264

Basidia, Berkeley's researches on, 230

Bauer, W. Hooker and, 144-145

Bauhin, Caspar, Pinax of, 14-15

---- and John, Morison on, 20

Bean, collections of, 248

---- on Yorkshire Fossil Flora, 247

Bentham, collaboration with Hooker, 313

---- bequest of, 144

---- collections of, 140

---- Herbarium of, 310

Berkeley, Miles Joseph, life of, =225-232=

---- ---- fungal morphology and, 230-231

---- W. Hooker on, 227

---- as naturalist, 225-226

---- as plant pathologist, 231-232

---- as systematic mycologist, 227-230

---- as zoologist, 226

Binney, on Carboniferous plants, 253

---- on coal balls, 245

---- fossil plant tissues and, 307

---- Geological Survey and, 245-246

---- publications of, 246

Blair, on Morison and Ray, 31

Bobart, Jacob, Keeper of Oxford Physic Garden, 17

---- ---- the younger, 18

---- ---- ---- and Morison's work, 18, 23

---- ---- ---- influence on Ray, 43

Botanic gardens, of British colonies, 136

---- ---- of Calcutta, 181-182, 305

---- ---- of Cambridge, 153

---- ---- Chelsea Physic, 84, 92, 179

---- ---- of Glasgow, 129, 130, 292

---- ---- Glasnevin, 213

---- ---- Government subsidy of, 288

---- ---- Kew, 136-137

---- ---- Oxford, 17, 18

---- ---- purpose of, 281

---- ---- rivalry between Edinburgh, 282, 283

_Botanical Gazette_, Henfrey and, 201, 202

_---- Magazine_, editorship of W. Hooker, 142

Botanical Society of Edinburgh, founding of, 294

Botanical illustration, Bauer and, 179

---- ---- Berkeley and, 226

---- ---- Dickson and, 301

---- ---- W. Fitch and, 141-142, 246

---- ---- Grew and, 52

---- ---- Harvey and, 202, 206, 212

---- ---- Hill and, 100, 102, 103

---- ---- W. Hooker and, 141

---- ---- Lindley and, 170, 174

---- ---- McGillivray, 244

---- ---- Tuffen West and, 200

---- ---- Williamson and, 257

Botany, local study of, 249

Botany teaching, Henslow's methods, 158, 159

---- ---- pioneers of, 281, 296

Bottomley, on Gilbert, 233-242

Bower, F. O., 258

---- on W. Hooker, 126-150

---- on J. D. Hooker, 302-323

Boyle, influence on Hales, 66

Bridging species, Ward on, 277

British Algae, Berkeley on, 226

British Flora, Bentham and Hooker on, 315

---- ---- Berkeley on, 227-228

---- ---- W. Hooker on, 143

---- ---- J. D. Hooker on, 315

Brome grass, Ward on, 276-277

Brongniart, Williamson and, 254-256

---- antiquity of Dicotyledons and, 244

---- on fossil seeds, 257

---- influence of, 246

Broome, collaboration with Berkeley, 229

Brown, Robert, life of, =108-125=

---- ---- J. Banks and, 110, 111

---- ---- collections of, 112

---- ---- Cycad ovule and, 187

---- ---- diary of, 111

---- ---- Griffith and, 186

---- ---- Linnean Society and, 112, 123-124

---- ---- on the ovule, 184-185

---- ---- period of, 134

---- ---- on vegetation of New Holland, 113

Brownian movement, 120

_Bryophyta_, Griffith and, 188-189, 190

Bud protection, Grew on, 50

_Calamites_, Williamson on, 253, 254, 256

---- secondary growth in, 254

Calcutta Gardens, Falconer and, 305

---- ---- Griffith and, 181-182

Cambridge, Ward at, 262

---- Botanic Gardens, 153

---- Herbarium, Lindley's presentation to, 170

Cambridge Philosophical Society, founding of, 151

---- ---- ---- presentations to, 152-153

---- ---- ---- Ward and, 276

---- Professorship, 152, 274

Carboniferous period, Binney on, 246, 253, 307

---- ---- J. D. Hooker on, 307

---- ---- Williamson on, 4, 253, 256

Cell structure, discovery of, 53

---- ---- Grew on, 53-54

---- theory, Williamson and, 251

Cesalpino, Andrea, abstract of results of, 12, 13

---- ---- classification and, 11

---- ---- on Cryptogams, 21

---- ---- Morison and, 26

---- ---- Theophrastus and, 11

Ceylon Flora, Hooker and, 312, 313

Chelsea Physic Garden, Botany lectures at, 84

---- ---- ---- Griffith and, 179

---- ---- ---- Hill's use of, 92

Chemiotaxis, R. Brown on, 115

---- Myoshi on, 275

---- Pfeffer and, 275

Chlorophyll, Grew's observations on, 59

Circumpolar uniformity, Hooker and, 321

Classification, Adanson on, 41

---- Bauhin and, 14

---- Cesalpino and, 11

---- De Candolle and, 41

---- first attempt at, 9

---- flower and fruit in, 11

---- Gesner on, 10

---- Hill on, 100

---- historical review of, 173

---- Jung and, 15

---- de Jussieu on, 41

---- leaf in, 21

---- Lindley and, 172, 173

---- Malpighi on, 35

---- Morison and, 18, 22

---- natural system of, 13, 41, 172, 173

---- progress in, 9

---- Ray on, 29

Climbing plants, anatomy of, 55

Coal-balls, first investigation of, 245

---- Williamson and, 251

Coffee disease, investigations of, 263

Coleridge, on Grew, 46, 47

Constancy of species, W. Hooker on, 148

Contact stimulus, Hill on, 98, 99

Controversies, Gilbert and Liebig, 238

---- Hill's, 89-91

---- Morison and Ray, 21, 31

---- Rothamsted and German physiologists, 242

---- Williamson and Brongniart, 254

Copley medal, Hales and, 70

Coprolite, discovery of, 155-156

Corn laws, Lindley and repeal of, 169

Cotyledons, Malpighi on, 35, 36

---- systematic value of, 36

Croonian lecture, Timiriazeff's, 80

Cryptogamic botany, Berkeley and, 4, 226

---- ---- W. Hooker and, 128

Cryptogamist, Ward as Government, 262

Cryptogams, R. Brown on, 121, 122

---- Cesalpino and, 21

---- Griffith and, 188-191

---- Harvey and, 4, 205

---- Williamson and fossil, 254, 255

Cycads, R. Brown on, 114, 117, 187

---- relationships of, 254

---- _Zamia_ and, 253

_Cycas_, R. Brown on, 118, 119

---- Griffith on ovule of, 187, 188

Cytase, importance of, 267

Darwin, Charles, omission of, 5

---- ---- Harvey and, 221

---- ---- J. D. Hooker and, 303, 307, 308, 315, 316, 320, 322, 323

---- ---- _Index Kewensis_ and, 314

Darwin, Francis, on Hales, 65-83

Darwinism, Balfour and, 298

De Candolle, A. P., Prodromus of, 134

---- ---- classification of, 41, 42

De Candolle, A. P., work of, 109

Deep sea deposits, Hooker and, 307

---- ---- ---- Williamson and, 251

Development, on study of, 118

Dewar, on Gilbert, 234, 235

Dickson, Alexander, Edinburgh Professorship of, =300-301=

Dublin Herbarium, Harvey and, 211, 222

---- Professorships at, 210-211, 218

East India Company, Griffith and, 3, 180, 184

Ecology, J. H. Balfour and, 297, 298

---- Grew on, 61

---- Griffith and, 182

---- J. S. Henslow and, 152, 154

---- J. D. Hooker and, 321

---- scope of, 7

Economic botany, Berkeley and, 231

---- ---- Griffith and, 180

---- ---- W. Hooker and, 139

---- ---- Museum of, 137-138

Edinburgh Botanical Gardens, Mackay and Don and, 291

---- ---- ---- the McNabs and, 299

---- ---- ---- Rutherford and, 291

---- ---- Schools, rivalry of, 282

---- Medical School, 290, 295

Edinburgh Professors, J. B. Balfour on, =280-301=

---- ---- Charles Alston, 283-286

---- ---- William Arthur, 284

---- ---- J. H. Balfour, 293-300

---- ---- Dickson, 300-301

---- ---- Graham, 291-293

---- ---- John Hope, 286-290

---- ---- Charles Preston, 282-283

---- ---- Rutherford, 290-291

---- ---- Sutherland, 281-283

Elfving, Ward and, 264

---- on bacteria, 273

Embryogeny, Dickson on plant, 300

Embryo-sac, Ward on the, 262

_Encyclopædia Britannica_, on Hales, 68

---- ---- Ward and the, 265

Endosperm, Grew on, 63

Eriksson, on "rust" disease, 276

Evolution, Harvey and, 221

---- J. D. Hooker and, 316

Falconer, Herbarium of, 312

Farmer, J. B., on R. Brown, 108-125

Farming, J. S. Henslow and, 155

Ferments, Ward on, 270, 271

Ferns, Grew on spores of, 63

---- W. Hooker and, 144-148

---- Morison on, 21

---- sexuality in, 135

---- Williamson on, 254, 257

Field botany, Balfour and, 297

---- ---- Edinburgh School and, 296

---- ---- Graham and, 292

---- ---- W. Hooker and, 132

---- Hope and, 289

Fitch, W., as illustrator, 131, 141, 145, 146

Flora of British India, 312

---- of Britain, 43

---- of South Africa, 219

---- of Antarctic, 305, 311, 312

---- of Ceylon, 312, 313

---- of Scotland, 132

---- Fossil, 245, 252

---- ---- of Williamson, 248

---- ---- of Yorkshire, 247

Floras, migration of, 322

Flowers, Ray on morphology of, 35

---- Grew on anatomy of, 52, 62

Food solutions, Grew on, 60

_Foraminifera_, Williamson on, 250, 251

Fossil botany, Binney and, 243, 307

---- ---- Brongniart and, 244

---- ---- R. Brown and, 122

---- ---- in England, 243

---- ---- in France, 254, 255

---- ---- J. D. Hooker on, 243, 307

---- ---- Lindley on, 176

---- ---- Williamson and, 7, 256, 259

---- ---- Witham and, 243

---- plants, development in, 258

Fossils, Williamson's collections of, 258

Frankland, Percy, Ward and, 271

Fungi, J. Banks on, 275

---- basidia in, 230

---- Berkeley on, 229

---- ---- Berkeley and Broome on, 229-230

---- classification of, 227-230

---- on epiphyllous, 263-264

---- Eriksson on, 276

---- on exotic, 228

---- J. S. Henslow on, 156, 157

---- Kew collections of, 228

---- life-history of, 271

---- morphology of, 230-231

---- nutrition of, 265

_Gardeners' Chronicle_, editorship of Lindley, 166, 169

Gardening, Williamson and, 252

Gatty, Mrs, on seaweeds, 216, 221

_Genera Filicum_, 144, 145, 147

_---- Plantarum_, of Bentham and Hooker, 313

---- ---- of Endlicher, 314

---- ---- of de Jussieu, 314

---- ---- of Linnaeus, 314

Genera, Tournefort and, 40

Geographical distribution, of Fungi, 228, 229

---- ---- J. D. Hooker on, 319-322

Geological zones, Williamson and, 248

Geology, Binney and, 245, 246

---- Father of English, 247

---- of Yorkshire, 247

---- Williamson and, 251

Geotropism, Grew on, 59

Gesner, classification and, 10, 11

Gilbert, Sir Joseph Henry, life of, =233-242=

---- ---- career of, 234

---- ---- chemical training of, 233-234

---- ---- Hellriegel and, 240

---- ---- Lawes and, 233

---- ---- Rothamsted and, 234

Ginger-beer plant, Ward on, 269, 270

Glasgow, Botanic Gardens at, 129, 130, 292

---- W. Hooker and Professorship of, 130-133

Glasnevin, Harvey and Botanic Gardens of, 213

Goebel, on W. Hooker, 148, 149

---- on _Bryophyta_, 189

Golden age, of Botany, 193-194

Graham, Edinburgh Professorship and, =291-293=

---- Glasgow Gardens and, 292

---- teaching and, 292, 293, 299

Grand'Eury, Williamson and, 253

Graphical method, Ward and, 276

Gray, Asa, 224, 321

Greeks, Botany of, 9

Greenhouses, ventilation of, 81

Greville, W. Hooker and, 144, 147

Grew, Nehemiah, life of, =44-64=

---- ---- anatomy and, 47-57, 135

---- ---- Hales and, 81

---- ---- Malpighi and, 48

---- ---- Schleiden and, 48

---- ---- versatility of, 45

Griffith, William, life of, =178-191=

---- ---- botanical work of, 180

---- ---- collections of, 182

---- ---- contemporaries of, 183

---- ---- Herbarium of, 312

---- ---- methods of, 183

---- ---- morphology and, 182-183

---- ---- travels of, 180-182

---- ---- University College and, 179

Griffiths, Mrs, on algae, 211, 223

Growth, Hales on, 82

---- logarithmic curve of, 273

Gwynne-Vaughan, on _Nymphaeaceae_, 199

Gymnosperms, R. Brown on, 117, 118

---- seeds of, 257

Hales, Stephen, life of, =65-83=

---- ---- Alston and, 285-286

---- ---- Chemistry and, 67, 78-80

---- ---- Physics and, 67

---- ---- Physiology and, 67, 71-78, 80-83

Hartog, Marcus, Williamson and, 255

Harvey, William Henry, life of, =202-224=

---- ---- collections of, 208-210, 216-218

---- ---- Darwin and, 221

---- ---- W. Hooker and, 207-208, 211, 219

---- ---- influence of, 221

---- ---- lectures of, 213-215

---- ---- publications of, 219

Hellriegel, on _Leguminosae_, 240-241, 267

Henfrey, Arthur, life of, =192-203=

---- ---- on critical species, 201

---- ---- on fertilisation, 195

---- ---- on sex in plants, 193-198

---- ---- Suminski and, 197-198

---- ---- text-books of, 200

---- ---- as translator and editor, 200

---- ---- work of, 192

Henslow, George, on Henslow, 151-163

Henslow, John Stevens, life of, =151-163=

---- ---- Berkeley and, 226

---- ---- botanical work of, 154

---- ---- collections of, 152-153

---- ---- Ecology and, 152-153

---- ---- Education and, 153-154, 158-159

---- ---- lectures of, 157

---- ---- on "rust" disease, 275

---- ---- scientific studies of, 151-152

---- ---- views of, 156

Herbalist, Hill as, 92, 100

Herbalists, work of, 47

_Herbals_, of Culpeper, 47

---- of Dodonaeus, 10

---- of Fuchs, 9

---- of Lobelius, 10

---- of Parkinson, 47

---- of Pierre Pena, 10

---- of Tragus (Bock), 9

Herbarium, of Falconer and Griffith, 312

---- Kew, 140

Herbs, classification and, 29, 30, 34

Hermann, work of, 26, 39

Hill, John, life of, =84-107=

---- ---- as actor, 85

---- ---- on anatomy, 93-96

---- ---- character of, 104-107

---- ---- as gardener, 93

---- ---- as herbalist, 92

---- ---- on Linnean method, 39

---- ---- on literature, 86-87, 92-93

---- ---- medical career of, 85

---- ---- methods of, 88

---- ---- on Natural History, 87

---- ---- on physiology, 96-100

---- ---- as systematist, 103

---- ---- on taxonomy, 100-103

Hill, T. G., on J. Hill, 84

_Himalayan Journals_, Hooker's, 305

Hofmeister, influence of, 6

---- morphology and, 4

---- predecessors of, 135

---- work of, 186, 191, 194, 195

Hofmeisterian epoch, papers of, 198

Hooke, on anatomy, 135

---- on cellular structure, 53

---- microscope and, 53

Hooker, Sir Joseph Dalton, life of, =302-323=

---- ---- as Administrator, 308-311

---- ---- Bentham and, 313

---- ---- Darwin and, 303, 316-319

---- ---- early life of, 302-303

---- ---- Edinburgh and, 293

---- ---- Essays of, 319-322

---- ---- as Geologist, 307-308

---- ---- as Systematist, 311-315 ---- ---- as Traveller, 304-307

Hooker, Sir William, life of, =126-150=

---- ---- Berkeley and, 227

---- ---- collections of, 139, 140

---- ---- on cryptogams, 227

---- ---- diagnosis and, 147-148

---- ---- Floristic works of, 143-145

---- ---- Glasgow and, 127, 129

---- ---- _Icones Plantarum_, 143

---- ---- Journals and, 142-143

---- ---- Kew and, 127, 130, 133-134, 136, 140, 149

---- ---- Linnean Society and, 127

---- ---- as Naturalist, 126-127

---- ---- as Pteridologist, 144-148

---- ---- as Systematist, 148-149

---- ---- teaching and, 130-132

Hookerian collections, Kew and, 310

Hope, life of, =286-290=

---- Alston and, 287

---- Botanic Gardens and, 288

---- de Jussieu and, 287

---- physiology and, 286-289

Horticulture, Lindley and, 3, 171, 172

How, British Flora and, 43

Hutton, Fossil botany and, 176-177

Huxley, lectures of, 261

---- on mutability of species, 317

_Icones Plantarum_, W. Hooker and, 143

Imbibition of water, Hales on, 75-76

---- ---- Sachs on, 76

Immunity, Grass and, 276

---- Ward on, 266

_Index Kewensis_, origin of, 314

India, J. D. Hooker's flora of, 312

---- J. D. Hooker's travels in, 306

Ingenhousz, on plant nutrition, 69

Insectivorous plants, J. D. Hooker on, 308

Ipswich Museum, J. S. Henslow and, 156, 159, 160

Jackson, Daydon, _Index Kewensis_ and, 314

Jodrell Laboratory, Ward at, 262

---- ---- Williamson and, 259

Judd, on Williamson, 251

Jung, Linnaeus and, 15

---- Ray and, 35

---- Systematic botany and, 15

de Jussieu, de Candolle and, 41, 42

---- classification and, 109, 134, 287

---- Tournefort and Ray and, 42

Keeble, F., on Lindley, 164-177

Kew Gardens, Administration of, 309-310

---- ---- Bentham's gifts to, 140

---- ---- Hales and, 81

---- ---- Herbarium at, 305

---- ---- Herbarium and Library at, 141, 310

---- ---- Hill and, 93

---- ---- W. Hooker Director of, 127, 130, 133-4, 136-7, 140, 149

---- ---- the two Hookers at, 308-309

---- ---- Lindley and, 136-138, 169-170

---- ---- Mycological Herbarium at, 231

---- ---- Orchid Herbarium at, 170

---- ---- Thiselton-Dyer and, 81, 150, 203, 259

Kidston, Witham's collection and, 245

_Kingia_, R. Brown on, 117

King's Botanist, Alston as, 283

---- ---- Arthur as, 284

Knaut, work of, 26, 39

Lang, on Griffith, 178-191

Lankester, E., 193

Lankester, Ray, on _Schizomycetes_, 265

Lawes, agriculture and, 235

---- Gilbert and, 235-236

---- on nitrogen assimilation, 267

Leaves, classification on form of, 21

---- movements of, 96-99

---- structure and functions of, 96-97

---- vernation of, 50

Leguminous nodules, Gilbert on, 239

---- ---- Hellriegel and, 240

---- ---- Ward on, 267

_Lepidodendron_, Williamson and, 258

Lichens, Ward on, 264, 270

Liebig, mineral theory of, 237-240

---- controversy with Gilbert, 238

Light on plants, Hales and, 80, 81

---- ---- Hill on, 97

Lily disease, Ward on, 266, 267

Lindley, John, life of, =164-177=

---- ---- activities of, 166

---- ---- J. Banks and, 168

---- ---- _Botanical Register_ and, 174

---- ---- characteristics of, 177

---- ---- on cryptogams, 195

---- ---- on Darwin, 174

---- ---- Horticulture and, 171

---- ---- Hutton and, 245, 248

---- ---- Library and, 174, 177

---- ---- literary work of, 169-174

---- ---- Professorship of, 168, 169

---- ---- Williamson and, 250

Linnaeus, British botany and, 6

---- Hope and, 286

---- Jung and, 15

---- on Morison and Cesalpino, 27-28, 42, 43

---- on Ray, 38, 42, 43

---- Taxonomy and, 6

---- method, 2, 3, 39

---- ---- Adanson and, 41

---- ---- Hill and, 101-103

---- ---- England and, 39, 40

---- period, 109, 134

---- system, Alston on, 285

---- ---- Hope on, 289

---- ---- influence of, 193

Linnean school, influence of, 195

Linnean Society, R. Brown and, 111, 112, 114, 121-124

---- ---- Berkeley and, 232

---- ---- Darwin-Wallace Celebration, 317, 318

---- ---- Griffith and, 183-185

---- ---- Harvey and, 207

---- ---- Ward and, 263, 264

---- ---- publications of, 184-186, 253

London University, Botany teaching at, 179

---- ---- Henslow and, 154

_Loranthaceae_, Griffith on, 185-186

Lotsy, morphology and, 186

Lycopods, Williamson and, 256

Lyell, _Calamites_ and, 253

---- J. H. Hooker and, 308, 320

---- mutability of species and, 317

_Lyginodendron_, Williamson and, 256, 257

Malpighi, anatomy and, 44, 135, 286

---- Grew and, 6, 48, 63

---- Hales and, 67, 68, 81

---- on seeds and seedlings, 35, 36

Manchester, Geological Society of, 245

---- Natural History Society of, 249

---- Professorship at, 250

---- Ward and, 264

Mangroves, Griffith and, 186-187

Manures, experiments with, 234, 236, 237

---- effect of, 237

---- nitrogenous, 238

_Marchantia_, Henfrey on, 199

Massee, George, on Berkeley, 225-232

_Materia Medica_, Alston and, 285

---- ---- Hope and, 287-289

---- ---- the Prestons and, 283

---- ---- Sutherland and, 282

Mayow, Hales and, 66, 79

McNab, Edinburgh Botanic Gardens and, 291, 292, 299

Medullary rays, Grew on, 56

Metabiosis, Ward on, 270

Microscope, R. Brown and, 119, 120

---- Hill and, 94

Microtechnique, Henfrey and, 199

Microtome, Hill's use of, 94

von Mohl, protoplasmic continuity and, 199, 200

Morison, Robert, life of, =16-43=

---- ---- the Bauhins and, 20

---- ---- Cesalpino and, 26

---- ---- classification of, 19, 21

---- ---- method of, 22-25

---- ---- Ray and, 34, 35, 39

---- ---- on _Umbelliferae_, 22

---- ---- works of, 19-20

Morphology, Berkeley on Fungal, 230-231

---- Floral, 35

---- Foundation of Plant, 15

---- Griffith on, 179

---- Hofmeisterian epoch, 198

---- modern, 135

---- Ray's essays on, 35

---- of reproductive organs, 187

Museums, J. S. Henslow and, 160

---- Hill and, 87

---- W. Hooker and, 137-140

Mutability of species, 317, 320

Mycology, Systematic, 227

Mycoplasm theory, 274, 275

Myoshi, chemiotaxis and, 275

Nägeli, fertilisation in Ferns, 196

Nathorst, on Bennettiteae, 253

Natural History, Henslow and, 3

---- ---- Hill on, 87

---- ---- Ray on, 43

Nature Study, J. S. Henslow and, 161, 162

Newton, Hales and, 66, 72, 78, 80

Nitrogen assimilation, Gilbert and Lawes and, 238-241

---- ---- Hellriegel and, 240-241

---- ---- leguminous plants and, 240

---- ---- Ward and, 267, 268

---- theory, 237-241

Nucleus, R. Brown and, 119, 135

Nutation, Grew on, 60

---- Hales on, 74

Nutrition, Hales on, 72, 80, 83

---- Ingenhousz on, 69

---- transference of, 278

_Nymphaeaceae_, Henfrey on, 199

Oceanic islands, J. D. Hooker on, 321

Oliver, F. W., on Henfrey, 192-203

Oolitic plants of Yorkshire, 253

_Orchidaceae_, R. Brown and, 115, 116

---- Lindley and, 165, 174-176

Organography, Dickson and, 301

Origin of Species, J. D. Hooker's essay, 320

Ovule, R. Brown on, 117-119, 184-185

---- Griffith on, 185-188

---- Schleiden and, 185

Oxford, Professorship at, 16, 17

---- Gardens of, 16, 17, 27

Parasites, education of, 277

---- host of, 268

Parasitic habit, adoption of, 269

Parasitism, adaptive, 277

Permanence of species, Lindley and, 173

Philosophical Biology, J. D. Hooker and, 315-323

Philosophical Transactions, Ward and, 264, 266-267, 269, 270, 275

Phlogiston theory, 66, 79

Photosynthesis, 80

Plant diseases, Ward on, 268

Plant histology, early work in, 199

Plant nutrition, 69, 72

Plant pathology, 4, 231-232

Plant physiology, Agriculture and, 7

---- ---- Chemistry and, 7

---- ---- experimental, 68, 83

---- ---- founders of, 2, 6, 68

---- ---- Gilbert and, 234-235

---- ---- Grew on, 58, 60, 61

---- ---- Hales and, 71-78, 80-83

---- ---- Hope and, 287, 289

---- tissues, Grew on, 54

Plants, medicinal properties of, 47

Pleomorphism, Bacteria and, 265

---- _Uredineae_ and, 266

Pollen, Amici's discovery, 194, 195

---- R. Brown and, 115-116

---- chamber, in _Cycas_, 187-188

Polyembryony, 117

Popularisation of Science, 250

Potato disease, 231, 266

Praeger, R. L., on Harvey, 202-224

Presl, on Ferns, 145-147

Preston, C. and G., _Materia Medica_ and, 283

_Primofilices_ of Arber, 257

_Proteaceae_, R. Brown on, 114

Protective mimicry in _Orchidaceae_, 116

Protoplasm, von Mohl and, 135

_Pteridophyta_, Griffith on, 188

---- alternation of generations, 188-189

Pteridosperms, secondary growth in, 256

---- seeds of, 257

Q. J. M. S., Ward and, 263-266

Quaker Schools, Science in Irish, 205

Ray, John, life of, =28-43=

---- ---- on Classification, 28-29, 34, 36-38

---- ---- on floral morphology, 35

---- ---- influence of, 23, 109

---- ---- Jung and, 15

---- ---- _Methodus Plantarum_, 32-34

---- ---- on seeds and seedlings, 35

---- ---- on transmission of water, 68

---- Society, Harvey on, 210

Renaissance of Botany, 5, 193, 194, 203

Renault, Williamson and, 255

Reproduction, Hill's views on, 99-100

_Rhamnus infectorius_, Ward on, 267

Ringing experiments, Hales and, 76-77

Root pressure, Hales on, 77, 78

Roots, Grew on, 51, 53, 55, 56

Ross, J. D. Hooker's travels with, 303-305, 312

Rothamsted, experiments on plants, 234-241

---- experiments on animals, 241

---- publications, 235-236, 241

Royal Horticultural Society, Lindley and, 166, 168

Royal Society, Gilbert and, 234

---- ---- Grew and, 63

---- ---- Hales and, 70

---- ---- Henfrey and, 193

---- ---- Hill and, 88-91

---- ---- Hooker, J. D., and, 310-311

---- ---- Ward and, 279

---- ---- Williamson and, 251, 253, 257, 259

---- ---- medal, 172, 234, 279

Rust fungus, physiological species of, 276

Rutherford, Edinburgh Medical School and, 290

---- Chemical work of, 290

Sachs, on growth, 82

---- on Hales, 65, 67, 68

---- History of Botany, 65, 191, 193

---- on Hofmeister, 198

---- on physiology, 72, 74, 75

---- on Ray, 68

---- Textbook, 194

---- on transpiration, 72-74

---- on water transport, 76

---- on Ward, 262

_Schizomycetes_, Ward on, 265

Schleiden, fertilisation, 194-196

---- Grew and, 48

---- morphology and, 134, 185, 186, 197

Schwendener's Theory, Bornet and, 278

---- ---- Ward and, 264, 278

Science and Art Department, Ward and, 261

Scientific exploration, Golden age of, 304

Scott, D. H., on Williamson, 243-260

Scottish Flora, Hope and, 289

Seaweeds, Flora of, 219

---- Harvey and, 208, 210-212, 214, 216

---- systematic study of, 202

Secondary growth, in Cryptogams, 254-256

---- ---- systematic importance of, 254, 256

Seeds and seedlings, Grew on, 49, 62

---- ---- ---- Malpighi on, 35

---- ---- ---- Ray on, 35

Sex in plants, Alston on, 286

---- ---- ---- in Cryptogams, 195, 196

---- ---- ---- denial of, 285

---- ---- ---- in Ferns, 135, 196-197

---- ---- ---- in flowering plants, 194

---- ---- ---- Grew on, 61, 62

Shrubs, Ray's classification of, 30, 34

Sibbald, 281

Solms-Laubach, on Williamson, 256, 257

---- ---- on Scott, 258

Sorby, Williamson and, 251

South Kensington, Science Schools at, 261, 262

Species, critical, 201

---- "lumping" of, 201

_Species Filicum_, 145, 146

Spencer, Herbert, 80

_Sphenophyllum_, Williamson and, 255-256

Starch, extraction of, 160, 161

Stems, annual rings in, 57

---- comparative anatomy of, 51, 56

---- modified, 57, 58

---- secondary thickening in, 56

_Sternbergiae_, Williamson on, 252

_Stigmaria_, Williamson on, 257

Suminski, sex in Ferns, 196-197

---- and Schleiden's theory, 197

Susceptibility, Ward on, 268

Sutherland, Edinburgh Professor, =281-282=

Symbiosis, physiological aspect of, 269

---- fermentation and, 270

_Synopsis Filicum_, publication of, 146, 147

Systematic botany, Balfour and, 299

---- ---- Bauhin and, 14

---- ---- Berkeley on, 227-230, 231

---- ---- British School of, 6

---- ---- R. Brown and, 121

---- ---- Cesalpino and, 11

---- ---- Ferns and, 144-148

---- ---- first publication on, 32

---- ---- Founders of, 2

---- ---- Griffith and, 184

---- ---- Harvey and, 220

---- ---- W. Hooker and, 3, 127, 132

---- ---- J. D. Hooker, 311-315

---- ---- Lindley and, 3

---- ---- _Materia Medica_ and, 282

---- ---- Morison and Ray and, 6, 47

---- ---- Seventeenth Century and, 14

Taxonomy, Hill and, 100

---- Linnaeus and, 6

---- Ray on, 6

---- rise of, 202-203

Theophrastus, Botany and, 8, 9

---- Cesalpino and, 11

---- Hill and, 85, 86

---- influence of, 11

---- Jung on, 15, 35

---- Ray on, 35

Theory of Descent, J. D. Hooker and, 316

Thiselton-Dyer, 2, 81, 259

---- ---- anatomy and, 150

---- ---- New Botany, 203

---- ---- on Ward, 261-279

Thomson, Gilbert under, 233-234

---- J. D. Hooker and, 306, 312

Timiriazeff, 80

Tournefort, Alston on, 285

---- on Cesalpino, 27

---- on Ray, 38

---- on Morison, 27

---- on de Jussieu, 42

---- work of, 40

Tracheae, Grew on, 51, 57

Transmission of water, Hales on, 68

Transpiration, Hales on, 72-77

---- and Light, 81

Trees, classification of, 31, 34

Treub, 186, 187

Trimen, Ceylon Flora and, 312

Tulasne, on "rust" disease, 275

Turgescence, Hales and, 82

University College, London, Gilbert and, 232, 233-4

---- ---- ---- Griffith and, 179

---- ---- ---- Lindley and, 166, 168, 177

---- ---- ---- Williamson and, 249

_Uredineae_, Banks and, 275

---- Eriksson and, 276

---- Ward and, 263, 266, 274, 275

Vascular Cryptogams, classification of, 254-255

---- ---- Henfrey and, 194

---- system, of climbing plants, 55

Vegetable physiology, Weddell and, 248

Vernation of leaves, Grew on, 50

Vessels, Hill and function of, 95

---- Grew and formation of, 52

---- Grew and nature of, 55

---- Grew and spiral, 57

Vienna Congress and Hill, 104

Vines on Morison and Ray, 8

---- on Ward, 261, 262

Wallace and Darwin, 315, 317

Ward, Harry Marshall, life of, =261-279=

---- ---- at Cambridge, 274

---- ---- in Ceylon, 262-264

---- ---- at Cooper's Hill, 266

---- ---- at Manchester, 264

---- ---- methods of, 278-279

---- ---- on coffee disease, 262-264

---- ---- on bacteriology, 265-268, 271-274

---- ---- on symbiosis, 268-271

---- ---- on _Uredineae_, 266, 275-277

Warming, on Ecology, 321

Water supply, Ward on, 274

_Welwitschia_, J. D. Hooker on, 308

Wheat, experiments on, 236-237

Wieland, on fossil plants, 253

Wilfarth, 267

Williamson, William Crawford, life of, =243-260=

---- ---- collections of, 258

---- ---- early life of, 247

---- ---- as Fossil Botanist, 7, 253

---- ---- as Geologist, 249

---- ---- as Lecturer, 250, 251

---- ---- at Manchester, 250

---- ---- mistakes of, 257, 258

---- ---- as Naturalist, 248

---- ---- results of, 256

---- ---- Ward and, 264

---- ---- as Zoologist, 4

_Williamsonia_, 253

Witham, 243-245, 307

Yorkshire, palaeontology of, 247

_Zamia_, Williamson on, 253

Zoologist, Williamson as, 4

---- Berkeley as, 226

TRANSCRIBER'S NOTE

Italic text is denoted by _underscores_. Bold text is denoted by =equal signs=. Superscripts are denoted by ^ and have not been expanded. Subscripts in chemical formulae are denoted by _ eg CO_2.

Obvious typographical errors and punctuation errors have been corrected after careful comparison with other occurrences within the text and consultation of external sources.

All botanical terms in the text have been retained. Except for those changes noted below, misspelling by the authors, inconsistent or archaic usage, has been retained. For example, cell-walls, cell walls; sea-weed, seaweed; Linnæus Linnaeus;

p 69 'limped' changed to 'limpid'. p 106 'concensus' changed to 'consensus'. Footnote [105] 'completer' changed to 'more complete'. Footnote [112] 'p. 8*.' changed to 'p. 8.'. p 173 'Endogens' (repeated in list) changed to 'Exogens'. p 220 'deterrants' changed to 'deterrents'. p 248 'estuarian' changed to 'estuarine'. p 300 'Walker Arnott' changed to 'Walker-Arnott'.

Index: 'Anabaena' changed to 'Anabena'. Index: (De Candolle:) 'Prodomus' changed to 'Prodromus'. Index: 'Elfing' changed to 'Elfving'. Index: (Ward:) '261-279' made bold '=261-279='.