The nose is nevertheless one of the features of the face which is best adapted for investigations of this kind. Its length is determined by the point of attachment of the nasal bones to the frontal bone and the position of the nasal spine; its breadth at the bridge depends upon the angle formed by the nasal bones; its breadth at the base is more or less related to the anterior opening of the nasal fossæ. But the form and development of the cartilages, as well as the thickness of the nostrils upon two very similar skulls, can modify considerably the type itself of this organ; and the exterior nasal index can give no idea of these variations. The study of Topinard upon this subject, nevertheless, possesses a real interest; but from the point of view of the characterisation of races, the researches made by Broca upon the nasal osteological index, which we will discuss further on, has a much more important value. The characters drawn from the nose, which are observed upon the living body, are however most important. This organ is more or less pressed in, broad and flat among almost all Negroes, the greater part of the Yellow races, and certain allophylian Whites; it is on the contrary narrow and prominent in fair white races. These two general types moreover present variations of which drawings only can give any idea. I may say the same with reference to the mouth. The thousand differences of form and dimensions which it can exhibit, from the negro of Guinea with his enormous and, as it were turned up lips, to certain aryan or semitic Whites can neither be measured nor described. We can only point out the general characters when they become very pronounced. It may, however, be remarked that the thickness of the lips is very marked among all negroes, in consequence of their projection in front of the maxillary bones and the teeth. The mouth of the Negro presents another character which seems to me to have been generally neglected, and which has always struck me. It is a kind of clamminess at the outer border of the commissures, and which seems to prevent the small movements of the corner of the mouth which play such an important part in the physiognomy. The dissections of M. Hamy have explained these facts. They have shown that in the Negroes the muscles of this region are both more developed and less distinct than in the Whites.