The total absence of pigment, which may occur with the Negro as with the White, is termed albinism. This may be accompanied, if complete (that is to say, when, besides the white skin and hair, the iris is also deprived of pigment, and appears red), by somewhat serious affections of the eyesight. But, in every respect, albinos are weakly, and probably not fertile amongst themselves.
In considering from all points of view the nature of hair and pigmentation in general, we cannot help noticing a certain correlation between these two characters. In fact, to the white colouring of the skin corresponds, in a general fashion, wavy hair, the colouring of which varies often in accord with the colour of the eyes and the shades of the skin (white, fair, brown races); to the yellow colouring corresponds straight, smooth hair; to the reddish-brown skin, frizzy hair; and to the black, woolly hair.
CHAPTER II.
1. MORPHOLOGICAL CHARACTERS (continued).
Cranium or Skull: Cranial measurements—Orbits and orbital index—Nasal bone and nasal index—Prognathism—Head of the living subject: Cephalic index—Face—Eyes—Nose and nasal index in the living subject—Lips—Trunk and Limbs: The Skeleton—Pelvis and its indices—Shoulder blade—Thoracic limb—Abdominal limb—Proportions of the body in the living subject: Trunk and neck—Curve of the back—Steatopygy—Various Organs: Genital organs—Brain—Its weight—Convolutions—The neuron—Its importance from the psychical point of view.
HAVING treated of the body in its general aspect, we shall now examine from the morphological point of view its different parts: the head, trunk, limbs, etc., as well as their relations to each other and their reciprocal dimensions, both in the skeleton and the living subject.
Cranium or Skull.—This part of the skeleton forms the object of investigation of a very extended branch of anthropology called craniology.
Craniology must not be confounded with the cranioscopy of the phrenologists, a sham science founded by Gall, who wished to establish a connection between certain bumps or irregularities of the surface of the skull and the parts of the brain in which, as was pretended, were localised the different intellectual functions. It is now demonstrated that the inequalities of the external table of the cranium walls have no relation whatever with the irregularities of the internal table, and still less have they anything in common with the conformation of the various parts of the brain. But if there be no such direct connection as this between the cranium and the brain, there is nevertheless a certain remote relation between them, and the brain has attained such a development in man that the study of everything which concerns it, immediately or remotely, possesses great interest. This would alone suffice to explain the pre-eminent position assigned to craniology in the natural history of man. But there exist still other reasons why the study of the skull is one of the most cultivated branches of anthropology. As in the case of all the other mammals, the skull in man is one of the parts of the skeleton, and even of the entire body, which exhibits the greatest number of well-marked variations. The differences in the form and the dimensions of the skull in correlation with those of the brain and the masticatory organs, serve to distinguish races and species, both in man and other vertebrata. Besides, the teeth, which characterise not only genera but even families and orders of the mammifera, are always attached to the skull, though not forming part of the bony system. We may also observe that the skull, with the other bones of the skeleton, constitutes the only anatomical document of prehistoric man which has come down to us; it is only in studying it that we can connect and compare, from the point of view of physical type, existing with extinct races of mankind.