I. The special history of human races presents a considerable number of interesting physiological facts which are sufficiently different and well marked, to serve asdistinctive characters. We find in the tropics peoples remarkably abstemious, and living entirely upon vegetables, without their organism being injuriously affected; in the polar regions there are others who eat fat in quantities which would be rejected by our digestive organs; there are also some slight variations between the respiration, circulation, animal temperature, secretions, etc. of the White man and the Negro; the muscular energy and the manner in which it is employed, sometimes vary considerably in different races; general sensibility, and consequently aptitude for feeling pain, are very unequally developed. The same surgical operation will not cause as much pain to a Chinese as to a European.
But the greater number of these traits arise from peculiarities which do not belong to general considerations. Many are theresult of anterior facts, and are connected with conditions of life, habit, etc., sometimes even with beliefs and institutions. Even if we confined ourselves to a mere sketch, we should have to enter into details incompatible with the plan of this book, if we wished to discuss all these questions. I shall, therefore, here confine myself to pointing out some general phenomena to justify the above statements.
II. I will, in the first place, say a few words upon certain facts and ideas which have often been the occasion of animateddiscussion. I mean the degree of relation admissible between the development of the intelligence and that of the brain. This question may seem at first sight to belong almost entirely to the study of the individual. But, from the manner in which it has been applied to the appreciation of the intellectual power of races, it has acquired a real interest in general anthropology.
On no occasion, perhaps, has this question been treated more thoroughly and by more competent judges than by the Paris Anthropological Society in the great discussion of 1861. Many speakers took part in it, but the two principal champions of the rival doctrines were Gratiolet on the one hand, and M. Broca upon the other. Some of their statements, if taken literally, would lead us to imagine that an impassable gulf lay between them. If, however, we read them again, after the excitement of the moment has passed away, we find, from the summaries which they themselves have drawn up, that such is by no means the case, and that, far from their being divided in principle, it would not be difficult to effect an understanding between them.
Gratiolet considers “that power which lies in the brain, and which can only be estimated by its manifestations,” far more important than weight or form. But he is far from absolutely refusing to recognise the influence of cerebral development; he allows that below a certain limit the human brain no longer performs its functions in a normal manner. This limit he places at 900 grms. (31·74 oz.) in the female.
M. Broca raises the number to 907 grms. (31·99 oz.), and adds that, in the male, the limit is 1049 grms. (37 oz.). He attributes great importance to the volume of the brain, estimated either directly, by weight, or by the capacity of the cranium. But on several occasions he protests most strongly against the intention which might be imputed to him, of wishing to establish an absolute relation between the development of the intelligence and the volume or weight of the brain. “No well-instructed man,” he says, “would everthink of estimating the intelligence by measuring the encephalon.”
The two following tables, borrowed from M. Broca, will suffice to show the truth of these words: