As to the hair which may be seen on different parts of the body, a special mention is due to that of the head. All people have more or less hair on the head, and this gives also very good characters. Among these the most essential are drawn from the form presented by the transverse cut when examined under the microscope. In the yellow people, the Americans and the white allophyles, this cut is more or less circular. In the Aryans, of which we are a part, it is oval; in the negroes it takes the form of an elongated ellipse. It is evident that a circular cut indicates a cylindrical hair. Such hair is very coarse and stiff, and never curling or frizzled; an oval cut indicates a slight and regular flattening. In this form the hairs are finer, and may be made into curls or waves more or less marked. Finally, the elliptical cut can only appear when the hair is much flattened, almost like a thick ribbon. These are the finest, and these alone have the aspect of wool which characterizes the head of the negro.
Crosses between these different races sometimes produce very remarkable heads of hair. The negro crossed with the Brazilian produces the Cafuso, whose hair, forming an immense wig, is at the same time long, stiff, and kinked.
I would further enlarge upon these exterior characters, as being the ones of which we can most easily give account, but time fails me, and I pass to the second class of characters, to those which we must seek in the interior.
II. Anatomic Character.—The anatomic character may be drawn from the solid parts of the body, that is, the skeleton, from the soft parts, and even from the liquids. I shall at first confine myself particularly to those drawn from the head.
In the head itself we must distinguish the cranium from the face. The first encloses the brain, whence proceed the organs of sense, with the exception of those of touch, properly speaking. Above all, it is the seat of intelligence; on these various accounts it merits a separate examination.
The general form of the cranium, that is, the relation between the longitudinal and transverse diameter, furnishes an excellent character. When this relation is less than that of 100 to 78, the cranium is considered as elongated from front to back: it is dolichocephalic. When the relation varies from 100 to 78 or 80, the cranium is medium or average; we say it is mesocephalic. Finally, when the relation is from 100 to 80, and above, the cranium is considered short, and is said to be brachycephalic.
These forms sometimes characterize very large human groups. So almost all the negroes are dolichocephalic; nearly all the yellow people, and most of the Americans, are brachycephalic or mesocephalic. Among the whites, and even sometimes in two populations belonging to the same branch of the white race, we find the two ex-