The microcephalism of races, as well as of individuals, of small stature, must not be confounded with the true microcephaly of a dwarfed or imperfectly developed brain, which is invariably accompanied with mental imbecility. The Mincopies of the Andaman Islands are spoken of by Professor Owen as “perhaps the most primitive, or lowest in the scale of civilisation, of the human race.”[[160]] Mr. G. E. Dobson, in describing his first visit to one of their “homes,” says: “Although none of the tribe exceeded 64 inches in height, so that on first seeing them we thought the shed contained none but boys and girls, I was especially struck by the remarkable contrast between the size of the males and females.”[[161]] Dr. J. B. Davis has given, in the supplement to Thesaurus Craniorum, the dimensions of a male Mincopie skeleton in his collection. The age he assumes to have been about thirty-five. The internal capacity of the skull is 62 oz. (Calais sand), equivalent to 75.5 cubic inches, and the entire height of the skeleton is 58.7 inches. It belongs, says Dr. Davis, to a pigmy race, is small in all its dimensions, and is particularly small in the dimensions of the pelvis. Of their skulls, moreover, he adds, “it is somewhat difficult to determine the sex with confidence. They are all small (but this is a character of the race), they are delicate in development, and they have that fulness of the occipital region, and smallness of the mastoid processes, which are marks of femininism.”
Mr. Alfred R. Wallace connects the Mincopies with the Negritos and Semangs of the Malay peninsula, a dark woolly-haired race, dwarfs in stature. Dr. Davis says of the six Mincopie skulls in his collection, four male and two female, as well as of others which he has seen: “They are all remarkably and strikingly alike, not merely in size but in form also. They are all small, round, brachycephalic crania of beautiful form.” Moreover, though classed as “lowest in the scale of civilisation,” the Mincopies betray no deficiency of intellect. The admirable photographs which illustrate Mr. Dobson’s narrative show in the majority of them good frontal development. The brain is not, indeed, relatively small. Their canoes are made of the trunk of a tree, hollowed out; and Mr. Dobson remarks: “The construction of their peculiar arrows and fish-spears with movable heads exhibits much ingenuity, and the use of no small reasoning power in adapting means to an end.”
We are indeed too apt to apply our own artificial standards as the sole test of intellectual vigour; whereas it is probable that in the amount of acquired knowledge and acuteness of reasoning many savage races surpass the majority of the illiterate peasantry in the most civilised countries of Europe. Mr. Wallace, in viewing the subject in one special light, remarks: “The brain of the lowest savages, and, as far as we yet know, of the prehistoric races, is little inferior in size to that of the higher types of man, and is immensely superior to that of the higher animals; while it is universally admitted that quantity of brain is one of the most important, and probably the most essential of the elements which determine mental power. Yet the mental requirements of savages, and the faculties actually exercised by them, are very little above those of animals. The higher feelings of pure morality and refined emotion, and the power of abstract reasoning and ideal conception, are useless to them; are rarely, if ever, manifested; and have no important relations to their habits, wants, desires, and well-being. They possess a mental organ beyond their needs.”[[162]]
Here, however, it may be well to guard against the confusion of two very distinct elements. The higher feelings of pure morality and refined emotion are not manifestations of intellectual vigour in the same sense as is the power of abstract reasoning and ideal conception. It is not rare to find an English or Scottish peasant with little intellectual culture or capacity for abstract reasoning, but with an acutely instinctive moral sense. On the other hand, among the criminal class, it is by no means rare to find examples of wonderfully vigorous intellectual power applied to the planning and accomplishing of schemes which involve as much foresight and skill as many a triumph of diplomacy; but which at the same time seem to be nearly incompatible with any moral sense. Moreover, it is needless to say that intellectual vigour and high moral principle are by no means invariable concomitants in any class of society; nor can they be traced to a common source. Mr. Wallace recognises that “a superior intelligence has guided the development of man in a definite direction, and for a special purpose”; and such guidance involves much more than the mere evolution of a higher animal organisation. But, appreciating as he does the difficulties involved in any acceptance of a theory of evolution which assumes man to be the mere latest outgrowth of a development from lower forms of animal life, Mr. Wallace points out that “natural selection could only have endowed savage man with a brain a little superior to that of an ape, whereas he actually possesses one very little inferior to that of a philosopher.”
Yet neither Mr. Wallace, nor Professor Huxley when controverting this argument, withholds a due recognition of the activity of the intellect of the savage. No one indeed can have much intercourse with savage races wholly dependent on their own resources without recognising that, within a certain range, their faculties are kept in constant activity. The savage hunter has not merely an intimate familiarity with all the capabilities and resources of many regions traversed by him in pursuit of his game; his geographical information includes much useful knowledge of the topography of ranges of country which he has never visited. I found, on one occasion, when exploring the Nepigon River, on Lake Superior, that my Chippeway guides, though fully 500 miles from their own country, and visiting the region for the first time, were nevertheless on the lookout for a metamorphic rock underlying the syenite which abounds there; and they made their way by well-recognised land-marks to this favourite “pipestone rock.” While moreover the Indian, like other savages, is devoid of much of what we style “useful knowledge,” but which would be very useless to him, he is fully informed on many subjects embraced within the range of the natural sciences; and has a very practical knowledge of meteorology, zoology, botany, and much else which constitutes useful knowledge to him. He is familiar with the habits of animals, and the medicinal virtues of many plants; will find his way through the forest by noting the special side of the trunks on which certain lichens grow; and follow the tracks of his game, or discover the nests of birds, by indications which would escape the most observant naturalist. The Australian savage, stimulated apparently to an unwonted ingenuity by the privations of an arid climate, is the inventor of two wonderfully ingenious implements, the wommera or throwing stick, and the bomerang, which, when employed by the native expert, accomplish feats entirely beyond any efforts of European skill. Moreover, as Professor Huxley remarks, he “can make excellent baskets and nets, and neatly fitted and beautifully balanced spears; he learns to use these so as to be able to transfix a quartern loaf at sixty yards; and very often, as in the case of the American Indians, the language of a savage exhibits complexities which a well-trained European finds it difficult to master.” Again he goes on to say: “Consider that every time a savage tracks his game he employs a minuteness of observation, and an accuracy of inductive and deductive reasoning which, applied to other matters, would assure some reputation to a man of science, and I think we need ask no further why he possesses such a fair supply of brains. In complexity and difficulty, I should say that the intellectual labour of a good hunter or warrior considerably exceeds that of an ordinary Englishman.” Hence Professor Huxley is not prepared to admit that the American or Australian savage possesses in his brain a mental organ which he fails to turn to full account. But without entering on the questions of evolution and natural selection in all their comprehensive bearings, it is still apparent that the brain of the savage is an instrument of great capacity, employed within narrow limits.
In estimating the comparative size of the brain, it is seen to be necessary to discriminate between individuals or races of small stature and cases of true microcephaly. On the other hand, it is not to be overlooked that examples of idiocy are not rare where the head is of a fair average size, and where the mental imbecility is regarded as congenital. But in this as in other researches of the physiologist, he is limited in his observations mainly to the chance opportunities which offer for study; and not unfrequently the prejudices of affection arrest the hand of the student, and prevent a post-mortem examination in cases where science has much to hope for from freedom of investigation. Hence the data thus far accumulated in evidence of the actual structure, size, and weight, of the human brain fall far short of what is requisite for a solution of many questions in reference to the relations between cerebration and mental activity. From time to time men of science have sought by example, as well as by precept, to lessen such impediments to scientific research. Dr. Dalton left instructions for a post-mortem examination in order to test the peculiarity of his vision, which he had assumed to be due to a colouring of the vitreous humour; Jeremy Bentham bequeathed his body to his friend Dr. Southwood Smith, for the purposes of anatomical science; and the will of Harriet Martineau contained this provision: “It is my desire, from an interest in the progress of scientific investigation, that my skull should be given to Henry George Atkinson, of Upper Gloucester Place, London, and also my brain, if my death should take place within such distance of his then present abode as to enable him to have it for purposes of scientific investigation.” The will is dated March 10, 1864; but by a codicil, dated October 5, 1871, this direction is revoked, with the explanation which follows in these words: “I wish to leave it on record that this alteration in my testamentary directions is not caused by any change of opinion as to the importance of scientific observation on such subjects, but is made in consequence merely of a change of circumstances in my individual case.” The natural repugnance of surviving relatives to any mutilation of the body must always tend to throw impediments in the way of such researches; though it may be anticipated that, with the increasing diffusion of knowledge, such obstacles to its pursuit will be diminished. Thus far, however, notwithstanding the persevering labours of Welcker, Bergmann, Parchappe, Broca, Boyd, Skae, Owen, Thurnam, and other physiologists, their observations have been necessarily limited almost exclusively to certain exceptional sources of evidence, embracing to a large extent only the pauper and the insane classes; and in the case of the latter especially, the functional disorder or chronic disease of the organ under consideration renders it peculiarly desirable that such results should be brought, as far as possible, into comparison with a corresponding number of observations on healthy brains of a class fairly representing the social and intellectual status of a civilised community.
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.