CHAPTER VII.

DINOSAURS (_continued_).

"Everything in Nature is engaged in writing its own history: the planet and the pebble are attended by their shadows, the rolling rock leaves its furrows on the mountain side, the river its channel in the soil, the animal its bones in the stratum, the fern and the leaf inscribe their modest epitaphs on the coal, the falling drop sculptures its story on the sand and on the stone,--not a footstep on the snow or on the ground, but traces in characters more or less enduring the record of its progress."--Emerson.

In the year 1878 was announced one of the most fortunate discoveries known in the whole history of geological science--a discovery unique of its kind, and one which throws considerable light on the nature of the monster first discovered by Dr. Mantell. In that year came the good news that no less than twenty-three Iguanodons had been found in the colliery of Bernissart, in Belgium, between Mons and Tournai, near the French frontier. The coal-bearing rocks (coal-measures) of this colliery, overlain by chalk and other deposits of later age, are fissured in many places by deep valleys or chasms more than 218 yards deep. Though now filled up, they must at one time have been open gorges on an old land surface. Into one of these chasms were somehow precipitated twenty-three Iguanodons, numbers of fish, a frog-like animal, several species of turtles, crocodiles, and numerous ferns similar to those described by Mantell from the Weald. It it not easy to conjecture how this large and varied assemblage of animals came to be collected together and entombed in this one place, but possibly their carcases were swept by some flood into the chasm in which the remains were discovered. They were buried in clay interstratified with sand, a fact which was interpreted in accordance with the above suggestion.

M. de Pauw, the accomplished controller of the workshops in the Royal Museum of Natural History at Brussels, spent three whole years in extracting this splendid series of fossils from the pit-shaft, the bones being brought up from a depth of rather more than 350 yards. But at the end of this time it was only the rough material that had been got together, and every block containing bones requires a great deal of most careful labour before the bones in it are so exposed that they can be properly studied. Out of the twenty-three specimens, fifteen had, in the year 1883, been chiselled out, eight remaining to be worked at; and although five skilled workmen were then constantly at work, progress was necessarily slow.

In 1883, that is after seven years, two huge entire skeletons had been set up in a great glass case in the Courtyard of the Museum at Brussels, and these exhibit with marvellous completeness the structure of the extinct monster.[17] The work reflects the highest credit on M. de Pauw;[18] and the director of the Bernissart Mining Company, M. Fages, deserves the thanks of all scientific men for so liberally aiding this important undertaking. These specimens illustrate the conclusion, previously arrived at by Professor Huxley, that Dinosaurs, as a group, occupy a position in the great chain of animal life intermediate between reptiles and birds. Indeed, it is the opinion of this great authority, and of many naturalists of the present day, that whenever future discoveries may reveal the ancestry of birds, it will be found that they came from Dinosaurs, or that both originated from a common ancestor.

[17] In August, 1892, Mr. Dollo wrote, in answer to inquiries from South Kensington, to say that five are already mounted and exhibited, and five more are almost ready for mounting. He also stated that the remains represent twenty-nine individuals, not twenty-three, as above.

[18] _Geological Magazine_, January, 1885.

The specimens so skilfully set up by M. de Pauw represent two distinct species. The larger one, Iguanodon Bernissartensis, cannot be less than fifteen feet high, and, measured from the tip of the snout to the end of the tail, is rather over thirty feet long, covering nearly twenty-four feet of ground in its erect position (see Fig. 21). Iguanodon Mantelli is smaller and more slender looking, with a height of over ten feet, and a length of about twenty feet. (See Fig. 22.)

The huge three-toed impressions found in Sussex prove that the monster, although owning a body as large as that of an elephant, habitually walked on its hind legs! Some of the thighbones found by Dr. Mantell measured between four and five feet in length. It will be seen that the fore limbs are small in comparison to the hind limbs. A remarkable feature of the hand is the large pointed bone at the end of the thumb, forming a kind of spur. The conical shape of this bone found by Dr. Mantell, who had no clue to its place in the skeleton, led him to suppose that it was a horn answering to that of a rhinoceros--a conclusion which Professor Owen refused for various reasons to accept. The latter concluded that it belonged to the hand, and now we see that he was right. Unfortunately, certain popular works on geology, such as _Our Earth and its Story_ (Cassell) still continue to spread this error, by showing a (very indifferent) restoration of the Iguanodon with the impossible horn on its nose. It has been suggested that the spur was a weapon of offence, and that, when attacked, an Iguanodon may have seized its aggressor in its short arms, and made use of the spur as a dagger. But this is only conjecture, and perhaps the spur may have been useful in seizing and pulling down the foliage and branches of trees, or in grubbing them up by the roots. Detached specimens of this curious bone may be seen among the other remains of Iguanodon at South Kensington, and also some of the gigantic tracks already alluded to. (Gallery IV. on plan, Wall-cases 5 and 6; and Gallery XI., Wall-case 7.)

The Bernissart specimens even afford some evidence as to the nature of the integument, or skin, and this supports the idea previously held that the creature possessed a smooth skin, or, at least, only slightly roughened. The muzzle was quite toothless, and perhaps may have been sheathed in horn, like the beak of turtles--an arrangement highly useful for biting off the leaves of trees.

Probably it passed much of its time in the water, using its immense powerful tail as an organ of propulsion. When swimming slowly it may have used both sets of limbs, but when going fast it probably fixed its fore limbs closely beside its body, and drove itself through the water by means of the long hind limbs alone. Mr. Dollo, of Brussels, is preparing a final monograph on the Bernissart Iguanodons, a work to which palæontologists eagerly look forward. There cannot be much doubt that these unarmoured Dinosaurs were molested and preyed upon by their carnivorous contemporaries, such as the fierce Megalosaurus, previously described (p. 76). And with regard to this, Mr. Dollo makes the suggestion that, when on land, their great height and erect posture enabled them to descry such enemies a long way off. Their great height must also have stood them in good stead, by enabling them easily to reach the leaves of trees, tree-ferns, cycads, and other forms of vegetable life, which constituted their daily food. (See restorations, Plates VII. and VIII.)

Should the reader visit the "geological island" in the grounds of the Crystal Palace, he will see that Mr. Waterhouse Hawkins's great model Iguanodon there set up is by no means in accordance with the description given above; but we must remember how imperfect was the material at his command.

Another Dinosaur, of considerable dimensions, that flourished during the Wealden period was the Hylæosaurus, also discovered by Dr. Mantell, and so named by him because it came from the Weald.[19] In the summer of 1832, upon visiting a quarry in Tilgate Forest, which had yielded many organic remains, he perceived in some fragments of a large mass of stone which had recently been broken up and thrown in the roadside, traces of numerous pieces of bone. With great care he cemented together and fixed in a stout frame, all the portions of this block that he could find, and set to work to "develop" the block with his chisel. This work occupied many weeks, but his labour was rewarded by the discovery of certain new and remarkable features displayed by this monster; for it must have presented, when alive, a formidable array of bony plates and long sharp spines, the latter of which probably stood in bristling array along the back and tail, and other parts of the body. (Wall-case 4.) Of the spines no less than ten were found in this block, varying in length from five to seventeen inches, the largest being four inches thick. It is known that many lizards, such as Iguanas and Cycluras, have large processes with horny coverings, forming a kind of fringe or crest along the back, and, judging by analogy, Dr. Mantell concluded that this gigantic saurian was similarly armed with a row of large angular spines covered by a thick horny investment. As weapons of offence and defence, they were no doubt highly effective, but their precise arrangement is still a matter of speculation.

[19] From Greek--_hule_, wood, or weald; and _sauros_, lizard.

This first specimen displayed, besides the bony scutes and spines, a portion of the backbone, eleven ribs and portions of the pectoral arch. A second specimen was found near Bolney, in Sussex, and was unfortunately almost wholly destroyed by the labourers; but Dr. Mantell was able to obtain many of the bones, such as ribs and limb-bones, and they also indicated a reptile of great size. A third specimen was brought to light in Tilgate Forest in 1837; but, unfortunately, this also fell into the hands of the parish labourers, who were unacquainted with its value. Although with due care a much larger portion of the skeleton might have been kept, yet Dr. Mantell was able to obtain a fine series of twenty-six vertebræ belonging to the tail, with a total length of nearly six feet: the same spines were present here also.

No specimen of the skull of this strange monster is known, and no teeth that can be with certainty referred to it.

Mr. Waterhouse Hawkins's model at Sydenham, near the Iguanodon, was based on the above discoveries, which are insufficient, and is far from the truth.

* * * * *

The next monster to be described is one that has fortunately left to posterity a much better record of itself, and probably was not very unlike the Hylæosaurus of Mantell. This is the Scelidosaurus: so named by Professor Owen from the indications of greater power in the hind legs than in most saurians.[20] It is the only known example of an almost entire skeleton of an English Dinosaur, and the history of its discovery is rather curious. Some time previous to 1861, Mr. J. Harrison, of Charmouth, obtained from the Lower Lias of that neighbourhood portions of the hind limb of a Dinosaur, and, later on, a nearly complete skull. These specimens were described by Owen, and the genus was founded on them. Mr. Harrison, whose discovery aroused great interest, continued to search on the same spot, and was rewarded by finding all the rest of the skeleton, except most of the neck vertebræ. This was extracted in several blocks, and these, after careful "development" of the bones, were fitted together so as to exhibit the whole skeleton. This most valuable specimen can now be seen at South Kensington in a separate glass case, and is one of the treasures of the unrivalled gallery of fossil reptiles. The case is placed so that both sides of the specimen can be seen (Case Y, Gallery IV., on plan). Its length is about twelve feet; perhaps the individual it represents was not fully grown, but, on account of the absence of most of the neck vertebræ, it is impossible to give the exact length. Both hind limbs are entire and well seen, but of the fore limbs the hands are wanting. The former were provided with four "functional" toes--that is, toes that were used,--and one "rudimentary" or unused one. There were two big spines, one placed on each shoulder, and a series of long plates arranged in lines along the back and side. Plate IX. shows an attempted restoration of this remarkable Dinosaur based upon the skeleton just described. It seems to have been organised for a terrestrial rather than an aquatic life, but to have been amphibious, frequenting the margins of rivers or lakes. Professor Owen considers that the carcase of this individual drifted down a river emptying itself in the old Liassic Sea, on the muddy bottom of which it would settle down when the skin had been so far decomposed as to permit the escape of gases due to decomposition. In that case the carcase would attract large carnivorous fishes and reptiles, such as swarmed in this old sea, so that portions of the skin and flesh would probably be torn away before the weight of the bones had completely buried it in mud. In this way, perhaps, the loss of much of the external armature and of the two fore feet may be accounted for. The hind limbs, being stronger, were better able to resist such attacks, and they are therefore preserved. Like many other specimens, this fossil has, in the course of ages, been subjected to enormous pressure from overlying strata, causing compression and dislocation or fracture.

[20] From Greek--_scelis_, limb, and _sauros_, lizard.

But there were in existence during the long Jurassic period, other and even stranger forms of armoured Dinosaurs. One of these, only imperfectly known at present, was the many-spined Polacanthus.[21] This remarkable monster had the whole region of the loins and haunches protected by a continuous sheet of bony plate armour, rising into knobs and spines, after the fashion of the shield or carapace of certain extinct armadillos known as Glyptodonts (see Chapter XII.). A specimen of such a shield is to be seen in the collection at South Kensington (Wall-case 4). It is to be hoped that, some day, further remains of the Polacanthus will be brought to light, so that a restoration may become possible. Dr. Mantell had already pointed out certain analogies between Iguanodon and the huge extinct sloths of the South American continent, that flourished in the much more recent Pleistocene period; and this idea is now considerably strengthened by the later discoveries of armoured Dinosaurs. These are his words: "In fine, we have in the Iguanodon the type of the terrestrial herbivora which, in the remote epoch of the earth's physical history termed by geologists _the age of Reptiles_, occupied the same relative position in the scale of being, and fulfilled the same general purposes in the economy of nature, as the Mastodons, Mammoths, and Mylodons (extinct sloths) of the Tertiary period, and the existing pachyderms."

[21] From Greek--_polus_, many, and _acantha_, spine.

It is, perhaps, one of the most interesting discoveries of modern geology, that certain races of animals now extinct have in various ways assumed some of the characteristics presented by animals much higher in the scale of being, that flourish in the present day. It seems as if there had been some strange law of anticipation at work, if we may venture so to formulate the idea. It has already been shown how the great saurians Ichthyosaurus and Plesiosaurus presumed to put on some of the characters of whales, and to play their _rôle_ in nature, though they were only reptiles; how the carnivorous Dinosaurs acquired teeth like those now possessed by lions and tigers, which also are mammals; and now we find herbivorous Dinosaurs imitating the Glyptodon, an armadillo that lived in South America almost down to the human period. We shall not lose sight of this very interesting and curious discovery, for other cases will present themselves to our view in future chapters. The reader might ask, "If reptiles were able in these and other ways to imitate the mammals of to-day, or of yesterday, why should they not have been able to go a few steps further, and actually _become_ mammals?" The Evolutionist, if confronted with such a question, would say, that there is no evidence of Dinosaurs turning into mammals, but that both may have branched off at an early geological period (say the Permian) from a primitive group of reptiles, or even of amphibians.

It must be borne in mind that, during the "age of reptiles" (Mesozoic period), the mammalian type was but feebly represented by certain small and humble forms, probably marsupials. As far as we know, there were no big quadrupeds such as flourish to-day; therefore reptiles played their part, and in so doing acquired some of their habits and structural peculiarities. It is difficult for us, living in an age of quadrupeds, to realise this, and to picture to ourselves reptilian types posing as "lords of creation," or, to use a homely phrase, "strutting in peacock's feathers."

* * * * *

Leaving now the English herbivorous Dinosaurs, we pass on to those still more wonderful forms discovered of late years by Professor Marsh. The former have been treated at considerable length, first because they are English, and, as such, the history of their discovery possesses considerable interest; secondly, because their elucidation reflects the highest credit on our great pioneers in this fruitful field of research, and illustrates the manner in which great naturalists have been able to draw most important and wonderful conclusions (afterwards verified in most cases) from material apparently far from promising. For example, Cuvier's prophecy of the Iguanodon from a few teeth is a striking example of the result of reasoning from the known to the unknown, an example which seems to us worthy to be ranked with the discovery of Neptune by Adams and Leverrier, or, to take a more recent case, the discovery by Mendeleef of the Periodic Law, by means of which he has foretold the discovery of new chemical elements.

Whatever may have been the origin of the great mammalian class, the possibility and even probability of birds and Dinosaurs being descended from a common ancestor is a theory for which much may be said, and it has been adopted by many leading naturalists of the present day, who have been convinced by Professor Huxley's clear elucidation of the nature of the pelvic region in the group of Dinosaurs which has been above described (the Ornithopoda, or bird-footed group). It was Professor Huxley who first propounded this interesting speculation, basing his belief on the many bird-like characters presented by this strange group of extinct reptiles--the small head and fore limbs, the long and often three-toed hollow hind limbs, the bones of the pelvis or haunch, their habit of walking in a semi-erect position on those limbs (as proved by their tracks), and in some of hopping, as the little Compsognathus most probably did. And, last but not least, the strange mixture of bird-like and reptilian characters presented by certain most anomalous birds discovered by Professor Marsh in American Cretaceous rocks, viz. the huge Hesperornis and the smaller Ichthyornis. Speaking on this subject some years ago, Professor Marsh said, "It is now generally admitted by biologists who have made a study of vertebrates, that birds have come down to us through the Dinosaurs, and the close affinity of the latter with recent struthious birds (ostrich, etc.), will hardly be questioned. The case amounts almost to a demonstration, if we compare with Dinosaurs their contemporaries, the Mesozoic birds. The classes of birds and reptiles, as now living, are separated by a gulf so profound that a few years since it was cited by the opponents of Evolution as the most important break in the animal series, and one which that doctrine could not bridge over. Since then, as Professor Huxley has clearly shown, this gap has been virtually filled by the discovery of bird-like reptiles and reptilian birds. Compsognathus and Archæopteryx of the Old World, and Ichthyornis and Hesperornis of the New, are the stepping-stones by which the Evolutionist of to-day leads the doubting brother across the shallow remnant of the gulf, once thought impassable."[22]

[22] _The Introduction and Succession of Vertebrate Life in America._ An address delivered before the American Association for the Advancement of Science, at Nashville, Tenn., August, 1877. See _Nature_, vol. xvi.

We now pass on to describe two of the strangest and most wonderful of all the Dinosaurs, recently discovered in the far West. The first of these is the Stegosaurus,[23] or plated lizard, not wholly unknown before, because part of its skeleton was found some years ago in a brickfield in the Kimmeridge Clay at Swindon. It has been proved that some of the bones to which the name Omosaurus[24] has been applied really belonged to the former genus.

[23] Greek--_stegos_, roof or covering; _sauros_, lizard.

[24] Greek--_omos_, humerus, and _sauros_, lizard.

With such complete specimens now known by Professor Marsh's descriptions, it will not be necessary to mention the meagre remains discovered in this country, or the conclusions arrived at by Owen and Seeley, interesting as they are.

In the year 1877 Professor Marsh described, in the _American Journal of Science_, a considerable portion of a skeleton of a Stegosaur, remarking that this genus proved to be one of the most remarkable animals yet discovered. It was found on the eastern flank of the Rocky Mountains, in strata of Jurassic age; they indicated an animal about twenty-five feet long, and for this discovery Science is indebted to Professor A. Lakes and Engineer H. C. Beckwith of the United States Navy, who found the remains in Colorado, near the locality of the gigantic Atlantosaurus. The solid limb-bones seem to point to an aquatic life, but there can be little doubt that the monster did not pass all its time in the water. (Fig. 25 shows the skeleton.)[25]

[25] The writer is informed that this skeleton is not yet mounted in the Yale College Museum, but that it will be before long. Our artist has drawn it as if set up, with a man standing by for comparison.

In 1879 Professor Marsh announced the discovery of additional remains from several localities. The most striking feature--from which the Stegosaur takes its name--was the presence of huge bony plates belonging to its skin, as well as large and small spines. Some of the plates were from two to three feet in diameter, and they were of various shapes. Of the spines, some were of great size and power, one pair being each over two feet long! The skull was remarkably small, and more like that of a lizard than we find in most Dinosaurs; the jaws were short and massive. Little was known at first of the brain, but fortunately a later discovery showed the brain-case well preserved. Later still, more than twenty other specimens of this Dinosaur were obtained, so that nearly every portion of the skeleton is now known. The skulls indicate that the creature possessed large eyes and a considerable power of smell. The jaws contain but a single row of teeth in actual use; but as these wore out, they were replaced by others lodged in a cavity below. Teeth, however, were not its strong point; they indicate a diet of soft succulent vegetation. The vertebræ have the faces of their centra more or less bi-concave. Many curious features in the skeleton can only be explained with reference to the heavy armour of plates and spines with which the Stegosaur was provided. Thus the vertebræ have their "neural spines" expanded at the summit to aid in supporting part of the armour. (See Fig. 26.) The fore limbs were short and massive, but provided with five fingers; the hind limbs were very much larger and more powerful. These and the powerful tail show that the monster could support itself on them as on a tripod, in an upright position, and this position must have been easily assumed in consequence of the massive hind quarters. As in Iguanodon, there were three toes to the hind feet, and these were probably covered by strong hoofs. The fore limbs could move freely in various directions like a human arm, and were probably used in self-defence. (See Fig. 27.) But for this purpose the tail with its four pairs of huge spines would be very effective, and one could easily imagine that a single deadly blow from such a tail would be sufficient to drive away, if not to kill, one of the carnivorous enemies of the species. All the plates and spines were, during life, protected by a thick horny covering, which must have increased their size and weight. Such a covering seems to be clearly indicated by certain grooves and impressions that mark their surfaces. (See Fig. 28.) The largest plates are unsymmetrical, and were probably arranged along the back, as in our restoration, Plate IX. It will be noticed, by those who are familiar with our first edition that Plate X. gives a somewhat different representation of the Stegosaur, in which the length of the hind limbs is more apparent, and also they are more free from the body.

Finally, the Stegosaur displays a rather remarkable feature; for a very large chamber was found in the sacrum[26] formed by an enlargement of the spinal cord. The chamber strongly resembled the brain-case in the skull, but was about ten times as large! So this anomalous monster had two sets of brains, one in its skull, and the other in the region of its haunches! and the latter, in directing the movements of the huge hind limbs and tail, did a large share of the work. The subject is a highly suggestive one, but at present requires further explanation.

[26] The sacrum may be thus defined: the Vertebræ (usually fused together) which unite with the haunch-bones (_ilia_) to form the pelvis.

On the walls of the fossil reptile gallery at South Kensington the reader will find a large framed drawing of the skeleton of Stegosaurus, kindly sent by Professor Marsh, whose forthcoming monograph will be welcomed by all palæontologists.

The last, and in some ways the strangest of the Dinosaurs, was the Triceratops[27] that flourished in America at the end of the long Mesozoic era, during the Cretaceous period. The name refers to the three horn-cores found on the skull, which probably supported true horns like those of oxen. Whereas the Stegosaur was provided with quite a small skull, this monster had one of huge dimensions and remarkable shape (see Figs. 29 and 30).[28] In the younger ones it was about six feet long, but in an old individual must have reached a length of seven or eight feet. Such a skull is only surpassed by some whales of the present day. Twenty different skulls of this kind have been found, and Professor Marsh places the horned Dinosaurs in a separate family, to which he has given the name Ceratopsidæ, or horn-faced. Their remains come from the Laramie beds, believed to be of Cretaceous age, but representing a remarkably mixed fauna and flora, so that some have considered them to be Tertiary. The strata containing these fossils are very rich in organic remains, and have yielded not only other Dinosaurs, but Plesiosaurs, crocodiles, turtles, many small reptiles, a few birds, fishes, and small mammals. The Ceratops beds are of fresh-water or brackish origin, and can now be traced for nearly eight hundred miles along the east flank of the Rocky Mountains.

[27] Greek--_treis_, three; _ceras_, horn; _ops_, face.

[28] This skeleton has not yet been set up in the Yale College Museum, but will be before long. Our artist has drawn it as if set up, with a man standing by for comparison. In an article in _The Californian Illustrated Magazine_ for April, 1892 (quoted in the _Review of Reviews_ for May), an American writer incorrectly describes this monster as "higher than Jumbo, and longer than two Jumbos placed in a row." But the article is altogether untrustworthy, and the two "restorations" are absurd.

In this Dinosaur we find the fore feet larger than usual in proportion to the hind limbs, and there can be no doubt that it walked on all fours. Its length was about twenty-five feet. All the vertebræ and limb-bones are solid. The brain was smaller in proportion to the skull than in any known vertebrate.

The teeth are remarkable in having two distinct roots. The wedge-like form of the skull is also very peculiar. The two large horns come immediately over the eyes, and the small one above the nose; this Dinosaur was, therefore, well provided with weapons of offence, such as would be highly useful in driving away or wounding carnivorous enemies. The back part of the skull rises up into a kind of huge crest, and this during life was protected by a special fringe of bony plates. Such an arrangement doubtless formed an effective shield to ward off blows when one Triceratops was fighting another, as bulls or buffaloes of the present day fight with their horns. The mouths of these Dinosaurs formed a kind of beak, sheathed in horn.

The body as well as the skull was protected, but the nature and position of the defensive parts in different forms cannot yet be determined with certainty. Various spines, bones, and plates have been found that evidently were meant for the protection of the creature's body, and belonged to the skin. Probably some of these were placed on the back, behind the crest of the skull; some may have defended the throat, as in Stegosaurus. Altogether, Triceratops is very different to any other Dinosaur. One cannot help picturing it rather as a fierce rhinoceros-like animal. In the restoration (Plate XI., Frontispiece) our artist has given it a thick skin, rather like that of the rhinoceros, only indicating small bony plates, etc., here and there.

Professor Marsh thinks that as the head increased in size to bear its armour of bony plates, the neck first, then the fore feet, and then the whole skeleton was specially modified to support it; and he concludes that as these changes took place in the course of the evolution of this wonderful Dinosaur, the head at last became so large and heavy that it must have been too much for the body to bear, and so have led to its destruction! This conclusion, if sound, is a warning against carrying "specialisation" too far. If we wished to write an epitaph on the tomb of the monster, it ought (according to Professor Marsh) to be, "I and my race died of over-specialisation."

After all these various efforts to improve themselves and to perfect their organisation so as to bring it into harmony with their surroundings, or "environment," as the biologists say, it seems rather hard that the Dinosaurs should have been extinguished, and their place in Nature taken by a higher type; but all things have their day, even Dinosaurs.

With regard to the difficulties, hardships, and dangers attending the discovery and transport of the remains, Professor Marsh's concluding remarks may be quoted here, since they give us a glimpse into the nature of his explorations in the far West that have now become so famous. He says, "In conclusion, let me say a word as to how the discoveries here recorded have been accomplished. The main credit for the work justly belongs to my able assistant, Mr. J. B. Hatcher, who has done so much to bring to light the ancient life of the Rocky Mountain regions. I can only claim to have shared a few of the dangers and hardships with him, but without his skill little would have been accomplished. If you will bear in mind that two of the skulls weighed nearly two tons each, when partially freed from their matrix and ready for shipment, in a deep desert cañon, fifty miles from a railway, you will appreciate one of the mechanical difficulties overcome. When I add that some of the most interesting discoveries were made in the hunting-grounds of the hostile Sioux Indians, who regard such explorations with superstitious dread, you will understand another phase of the problem. I might speak of even greater difficulties and dangers, but the results attained repay all past efforts, and I hope at no distant day to have something more of interest to lay before you."[29]

[29] _American Journal of Science_, vol. xli. p. 176.