The facility in parturition, so remarkable among the inferior races, has therefore, as a cause, a relative smallness in the head of the fœtus, even more remarkable. For we must admit that, among these people, everything happens naturally, as among animals; it is the laborious childbirth among ourselves which is exceptional and anomalous, and which requires to be explained. This difficult and painful parturition, which we so continually see, is, doubtless, the consequence of civilisation; only it is difficult to decide what may be its immediate cause, and if this cause resides in the mother or in the fœtus. Is it the pelvis which has been made narrower in the European by some custom in our manners--by some habit of education? or must we admit--and it is a serious question--that the development of such an organ as the brain _in the fœtus_, is subordinate to the exercise of the functions of the same organ in the progenitors? With the osseous system we may connect the differences of height which are so apparent. Who does not recognise that in Europe, for instance, the Anglo-Saxons, the Germans, the Norwegians, and the Albanians, are of great stature; whilst the inhabitants of the south of France, the Irish, the Spaniards,[117] and the Maltese, represent a shorter variety of the human race. The members show the most marked differences among the various races of mankind, by reason of the law which causes the modifications of organism to become more and more decided, and more and more clear from the centre to the periphery. Naturalists seek for characteristics of families and individuals in the fingers and in the teeth: it is in the extremes of an individual, in the colour of the hair or the skin, that we generally find the characteristics of species. We shall only quote in this place facts which may be the object of some particular remark.