Part 37

The average brain-weight of the human adult, as determined by a numerous series of observations, ranges for man from 40 oz. to 52½ oz., and for woman from 35 oz. to 47½ oz. But some indications among ancient crania tend to suggest a doubt as to whether this difference in cerebral capacity was a uniformly marked sexual distinction among early races; due allowance being made for difference in stature. Dr. Thurnam made the race of the British Long Barrows a special subject of study; and Dr. Rolleston followed up his researches with valuable results. Amongst other points, he noted that the males appear to have averaged 5 ft. 6 in., and the females 4 ft. 10 in. in height. But while the difference of stature between the male and the female exceeds what is observable in most modern races, the variation in the size and internal capacity of their skulls appears to be less than among civilised races. The like characteristics are noticeable in the larger race of Europe’s Palæolithic era. Nothing is more striking in the discovery of those ancient remains of European man than the remarkable development of the skulls and the good brain capacity of the race of the palæotechnic dawn, where man is proved, by his works of art and all the traces of his hearth and home, to have been still a rude hunter and cave-dweller. The Canstadt type of skull is assumed to be that of the earliest European race of which traces have thus far been discovered; and it is unquestionably markedly inferior in development to that of the artistic Troglodytes of the French Reindeer period. Yet remarkable examples of atavism, as in the skull of St. Mansuy, the missionary bishop of Toul, in Lorraine, in the fourth century, and in that of Robert the Bruce, show a reversion to this early type, in accompaniment with exceptional intellectual capacity. The Neanderthal skull, an extreme example of the primitive type, is pronounced by Professor Schaaffhausen to be the most brutal of all human skulls; though this impression is mainly due to the abnormal development of the superciliary ridges, in which it undoubtedly approximates to the chimpanzee or the gorilla. But it has an estimated capacity of 75 cubic inches, and a corresponding cerebral development in no degree incompatible with the idea that the remains recovered from the Neanderthal cave may be those of a skilled hunter; and one apt in the ingenious arts of the primitive tool-maker.

Whatever other changes, therefore, may have affected the brain as the organ of human thought and reasoning, it does not thus far appear that the average mass of brain has greatly increased since the advent of European man. Important exceptions have indeed been noted. Professor Broca’s observations on the cerebral capacity of the Parisian population at different periods, based on nearly 400 skulls derived from vaults and cemeteries of dates from the eleventh or twelfth to the nineteenth century, appear to him to show a progressive cerebral development in that centre of European civilisation.[163] But though the assumption is not inconsistent with other results of civilisation, and is the necessary corollary of the postulate that intellectual activity tends to development of brain, the fact that the crania presented a still greater diversity in type than in size reminds us of the intermixture of races on the banks of the Seine, and the consequent necessity for much more extended observations before so important a deduction can be received as an established truth.

Taking the average brain-weight of the human adult as already stated, all male brains falling much below 40 oz. or 1130 grammes, and female brains below 35 oz. or 990 grammes, may be classed as _microcephalous_; and all above the maxima of the medium male and female brain, viz. 52½ oz. or 1480 grammes, and 47½ oz. or 1345 grammes, may be ranked as _megalocephalous_, or great brains.

Professor Welcker, who devoted special attention to the whole subject under review, assumes another and simpler test when he says that skulls of more than 540 to 550 millimetres, or 21.26 to 21.65 inches in circumference—the weight of brain belonging to which is 1490 to 1560 grammes (52.5-55 oz. av.)—are to be regarded as exceptionally large. But while an excess of horizontal circumference may be accepted as indicating good cerebral capacity, it must not be overlooked that the adoption of it as the key to any definite or even approximate brain-weight ignores the important elements of variation involved in the difference between acrocephalic and platycephalic head-forms. The volume of brain in Scott, and probably in Shakespeare, appears to have depended more on its elevation than its horizontal expansion. The same was also the case with Byron. The intermastoid arch, measured across the vertex of the skull from the tip of one mastoid process to the other, furnishes an accurate gauge of this development. Of thirteen selected male English skulls in Dr. Davis’s collection, the mean of this measurement is 15.1; and of thirty-nine male and female English skulls, it is only 14.4. Of the whole number of eighty-one English skulls described in the _Thesaurus Craniorum_, three exceptionally large ones are: No. 123, that of an ancient British chief, of fully 6 ft. 2 in. in stature, from the Grimsthorpe Barrow, Yorkshire; No. 905, a calvarium of great magnitude, very brachycephalic, and with the elevation across the middle of the parietals apparently exaggerated by compression in infancy, from Hythe, Kent; and No. 1029, another male skull, remarkable alike for its size and weight, and with a peculiarity of conformation ascribed by Dr. Davis to synostosis of the coronal suture. The intermastoid arch in those exceptionally large skulls measures respectively 16.0, 16.2, and 16.9, whereas the same measurement derived from the cast of Scott’s head taken after death, yields the extraordinary dimensions of 19 inches. This last measurement is over the hairy scalp. But after making ample allowance for this, the vertical measurement of the skull and consequently of the brain is remarkable.

Full value has been assigned at all periods to the well-developed forehead. It is characteristic of man. The physiognomist and the phrenologist have each given significance to it in their respective systems; and it has received no less prominent recognition from the poets. A fully developed forehead is assumed as distinctive of the male skull. But Juliet, in _The Two Gentlemen of Verona_, when depreciating her rival, exclaims, “Ay, but her forehead’s low”; and the jealous Queen of Egypt, in _Antony and Cleopatra_, is told of Octavia that “her forehead is as low as she would wish it.” “The fair large front” of Milton’s perfect man is the external index of an ample cerebrum: the organ to which the seat of consciousness, intelligence, and will is assigned. It is therefore consistent with this that a low, retreating forehead is popularly assumed to be the characteristic index of the savage, and of the unintellectual among civilised races. But the cerebral characteristics of both ancient and modern civilised races have still to be studied in detail; and the influence of race and sex on the form of the head and the mass and weight of the brain, involves some curious questions in relation to the oldest illustrations of the physical characteristics of man, and to the effect of civilisation on the relative development of the sexes.

Early observations led Dr. Pruner-Bey and other ethnologists of France to recognise in certain ancient Gaulish skulls of a brachycephalic type the evidences of a primitive race, assumed to represent the inhabitants of France and of Central Europe during its Reindeer period, and which appeared to be assigned with reasonable probability to a Mongol origin. But in the Cro-Magnon cavern, and in other caves more recently explored, the remains of a race of men have been brought to light markedly dolichocephalic, and no less striking in cranial capacity. Dr. Broca speaks of these ancient cave-dwellers of the valley of the Vézère as characterised by “sure signs of a powerful cerebral organisation. The skulls are large. Their diameters, their curves, their capacity, attain, and even surpass, our medium skulls of the present day. The forehead is wide, by no means receding, but describing a fine curve. The amplitude of the frontal tuberosities denotes a large development of the anterior cerebral lobes, which are the seat of the most noble intellectual faculties.”

This primitive race of hunters, marked by such exceptional characteristics, belonged to the remote Reindeer period of Western Europe, and was contemporary with the mammoth, the tichorine rhinoceros, and the fossil horse, as well as with the cave-lion, the cave-bear, and other long-extinct carnivora of Europe. The remarkable evidence of their intellectual capacity has already been reviewed, in considering the manifestations of the artistic faculty among primitive races. Their weapons and implements, including carved maces or official batons, as they are assumed to be, contribute additional evidence of skill and latent capacity among a primitive race of hunters and cave-dwellers. Dr. Broca, after a consideration of the merits of their ingenious arts, says: “They had advanced to the very threshold of civilisation”; and Dr. Pruner-Bey thus comments on their characteristics: “If we consider that its three individuals had a cranial capacity much superior to the average at the present day; that one of them was a female, and that female crania are generally below the average of _male_ crania in size; and that nevertheless the cranial capacity of the Cro-Magnon woman surpasses the average capacity of male skulls of to-day, we are led to regard the great size of the brain as one of the more remarkable characters of the Cro-Magnon race. This cerebral volume seems to me even to exceed that with which at the present day a stature equal to that of our cave-folks would be associated; whilst the skulls from the Belgium caves are small, not only absolutely, but even relatively in the rather small stature of the inhabitants of those caves.”

The Canstadt head is undoubtedly an unintellectual type suggestive of an inferior, though not necessarily an older savage race; for the evidence of climate, contemporary fauna, and other indices of the environments of the Cro-Magnon cave-dwellers, all point to an early Post-Glacial era. Dr. Isaac Taylor, in his _Origin of the Aryans_, assuming the priority of the Canstadt man, speaks of him as “this primitive savage, the earliest inhabitant of Europe.” The forehead in this type is low and receding, and the cerebral capacity generally correspondingly inferior. The relative superposition in some discoveries of ancient human remains, as in the alluvium and gravels of a former bed of the Seine, at Grenelle, lends confirmation to the idea that in this poorly-developed cranial type we recover the physical characteristics of the earliest type of the European savage thus far brought to light. But no disclosure of regular sepulture, or of implements or carvings assignable to him, have hitherto furnished the means of determining his condition or mode of life.

The disclosures of the rock-shelters in the valley of the Vézère are, on the contrary, replete with interest, from the evidence they furnish of a race of savage hunters, in whom ingenious skill and great artistic aptitude gave evidence of latent intellectual capacity of a high order. The remarkable size of crania accompanying those examples of primitive art seemingly pertaining to the Troglodytes of the Mammoth and Reindeer periods of Central Europe, is the more significant from its bearing on the evidence of progressive cerebral development adduced by Dr. Broca from skulls recovered from ancient and modern cemeteries of Paris. It appears, indeed, to conflict with any theory of a progressive development from the Troglodyte of the Post-Glacial age to the civilised Frenchman of modern times. Professor Boyd Dawkins has accordingly been at some pains in his _Cave Hunting_ to show that the conclusions formed by previous observers as to the epoch of their burial are not supported by the facts of the case; and he sums up his review of the whole evidence by expressing a conviction that he “should feel inclined to assign the interments to the Neolithic age, in which cave-burial was so common. The facts,” he adds, “do not warrant the human skeletons being taken as proving the physique of the palæolithic hunters of the Dordogne, or as a basis for an inquiry into the ethnology of the palæolithic races. Professor Boyd Dawkins also pronounces the same doubts in reference to the equally characteristic male skeleton found in a cave at Mentone, and to others obtained in the Lombrive and other caves. It is not to be overlooked that the possibility of the intrusion of human remains into earlier strata constitutes an important element suggesting caution in reasoning from such evidence. For the remains of man differ from those of other animals found in such series of deposits as mark a succession of periods, in so far as they pertain to the only animal habitually given to the practice of interment. Human skeletons found under such circumstances may have been artificially intruded long subsequent to the accumulation of the breccia in which they lay. Happily, however, any doubts as to the contemporaneity of the human remains with the other cave relics has been removed by the discovery of skeletons, similar in type, in other caverns in the same valley—and especially in that of Laugerie Basse,—in positions which seem to leave no room for questioning their being of the same age as the works of art found along with them.

Other examples of the ancient man of Europe show him in like manner endowed with a cerebral development in advance of the rudest races of modern times. The skull found by Dr. Schmerling in the Engis cave, near Liège, along with remains of six or seven human skeletons, was embedded in the same matrix with bones of the fossil elephant, rhinoceros, hyæna, and other extinct quadrupeds. It is a fairly proportioned, well-developed dolichocephalic skull; and, like others of the ancient human skulls of different types thus far found, has signally disappointed the expectations of those who count upon invariably finding a lower type the older the formation in which it occurs. “Assuredly,” says Professor Huxley, “there is no mark of degradation about any part of its structure. It is, in fact, a fair average human skull, which might have belonged to a philosopher, or might have contained the thoughtless brain of a savage.” Even the famous Neanderthal skull, of uncertain geological antiquity, but pronounced to be “the most brutal of all human skulls,” acquires its exceptional character, as already noted, chiefly from the abnormal development of the superciliary region.

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It is a universally accepted fact that the size of the male head and the weight of the brain are greater than those of the female. The average weight of the male brain is found to exceed that of the female by about 10 per cent; or, as it is stated by Professor Welcker, the brain-weight of man is to that of woman as 100 to 90. But the difference of stature between the two sexes has to be taken into account. The average, based on various series of observations to determine the mean stature for man and for woman, shows the latter to be about 8 per cent less than the former; or, as Dr. Thurnam has stated it more precisely:

RATIO OF STATURE AND BRAIN-WEIGHT IN THE TWO SEXES

MALE. FEMALE. Stature 100 92.0 Weight of brain 100 90.3

Here again, however, it becomes important to take into consideration other elements of difference besides weight; for, as Tennyson insists, “Woman is not undevelopt man, but diverse.” The results of Wagner’s observations on the superficial measurements of the convolutions of the brain point to the conclusion that in the female the lesser brain-weight may be compensated by a larger superficies. Ranked in the order of their relative weights in grammes, six average brains of men and women were found to stand thus:—

1. Male (_a_) 1340 2. Male (_b_) 1330 3. Male (_c_) 1273 4. Female (_d_) 1254 5. Female (_e_) 1223 6. Female (_f_) 1185

But the same brains, when tested by the degrees of convolution of the frontal lobe, measured in squares of sixteen square millimetres, irrespective of the question of relative size, ranked as follows, advancing the female (_d_) from the fourth to the first place, and reducing the male (_c_) from the third to the sixth place:—

1. Female (_d_) 2498 2. Male (_a_) 2451 3. Male (_b_) 2309 4. Female (_f_) 2300 5. Female (_e_) 2272 6. Male (_c_) 2117

But, as already indicated, some modern disclosures tend to raise the question whether the difference between the sexes, in so far as relative volume of brain is concerned, has not been increased as a result of civilisation. The disparity in size between the Cro-Magnon male and female skeletons is quite as great as that of modern times, but the capacity of the female skull is relatively good.

Other observations, such as those of Professor Rolleston “On the People of the Long Barrow Period,” seem to indicate a nearer approximation in actual cranial capacity of the two sexes in prehistoric times than among modern civilised races. On the assumption that intellectual activity tends to permanent development of brain, it is consistent with the conditions of savage life that it should bring the mental energies of both sexes into nearly equal play. They have equally to encounter the struggle for existence, and have their faculties stimulated in a corresponding degree. As nations rise above the purely savage condition of the hunter stage, this relative co-operation of the sexes is subjected to great variations. The laws of Solon with reference to the right of sale of a daughter or sister, and the penalties for the violation of a free woman, show the position of the weaker sex among the Greeks at that early stage to have been a degrading one. But the change was great at a later stage; and much of our higher civilisation is traceable to the early establishment of the European woman’s rights, which Christianity subsequently tended to enlarge. The position of woman among the ancient Britons appears to have been one of perfect equality with man. Among the Arabians and other Mohammedan nations, including the modern Turks, the opposite is the case; and the whole tendency of the creed of the Koran, and the social life among Mohammedan nations, must be towards the intellectual atrophy of woman. Hence it is consistent with the diverse conditions of life that, in so far as cerebral development is the result of mental activity, a much closer approximation is to be looked for in the mass and weight of brain in the two sexes among savage races, than among nations where woman systematically occupies a condition of servile degradation, or of passive inertness.

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Some interesting results of the actual brain-weights of Negroes and other typical representatives of inferior savage races have been published, including examples of both sexes; and although the observations are as yet too few for the deduction of any absolute or very comprehensive conclusions, they furnish a valuable contribution towards this department of ethnical comparison. In 1865, Dr. Peacock published the results of observations on the brains of four Negroes and two Negresses; and to those he subsequently added a seventh example.[164] Others are included in the following table. But I have excluded some extremes of variation, such as the two given by Mascagni, one of which weighed 1458 grammes, or 51.5 oz. av., and the other only 738 grammes, or 26.1 oz. av. In addition to such actual brain-weights, Morton, Tiedemann, Davis, Wyman, and others, have gauged the skulls of Negroes, American Indians, Mincopies, Tasmanians, Australians, and other savage races, as well as those of many civilised and semi-civilised nations, and thereby contributed valuable data towards determining their relative cranial capacity. In his _Crania Ægyptiaca_, Dr. Morton, when discussing the traces of a Negro element in the ancient Egyptian population, says: “I have in my possession seventy-nine crania of Negroes born in Africa, for which I am indebted to Drs. Goheen and M’Dowell, lately attached to the medical department of the colony of Liberia, in Western Africa; and especially to Don Jose Rodriguez Cisneros, M.D., of Havana, in the island of Cuba. Of the whole number, fifty-eight are adult, or sixteen years of age and upwards, and give eighty-five cubic inches for the average size of the brain. The largest head measures ninety-nine cubic inches; the smallest but sixty-five. The latter, which is that of a middle-aged woman, is the smallest adult head that has hitherto come under my notice.”[165]

TABLE I

NEGRO BRAIN-WEIGHT

─────┬────────────────────────────────────┬────────────────────┬──────── │ │ │ Sex. │ Race. │ Authority. │Weight. │ │ │ ─────┼────────────────────────────────────┼────────────────────┼──────── │ │ │ M. │African, Mozambique │Peacock │ 43.80 M. │ „ │ „ │ 45.80 M. │ „ Buenos Ayres │ „ │ 44.00 M. │ „ Congo │ „ │ 46.25 M. │ „ │ „ │ 42.80 M. │ „ │Sœmmering │ 45.40 M. │ „ │Tiedemann │ 35.20 M. │ „ Congo │C. Luigi Calori │ 44.40 M. │ „ │Barkow │ 50.80 M. │ „ │ „ │ 45.90 M. │ „ │ „ │ 38.90 M. │ „ │Sir A. Cooper │ 49.00 F. │Hottentot Venus │Marshall │ 31.00 F. │Bushwoman │ „ │ 30.75 F. │ „ │ „ │ 31.50 F. │ „ │ „ │ 31.00 F. │ „ │Flower and Murie │ 38.00 F. │African │Peacock │ 46.00 F. │ „ │ „ │ 41.00 │ │ │ ─────┴────────────────────────────────────┴────────────────────┴────────