The variation of the colour of the hair is well known. Some general facts may nevertheless be collected from the midst of all these special cases. I have said already that we find isolated cases in all races of individuals with hair of a more or less reddish colour. Fair hair has for a long time been regarded as the appanage of a small number of Aryan groups. Nevertheless, according to Pruner Bey, we also meet with it sometimes among the Asiatic Semites, and we know for certain that they are very frequent among the Kabyles. Facts such as Pierre Martyr, P. Kes, James, etc., have noticed among the Parians, the Lee Panis, the Kiawas, etc., will no doubt one day be explained by migrations and intercrossings. It seems to me, for instance, almost evident that the Scandinavians must have introduced their fair hair among several tribes of the American shore, and that the facts noticed by Pierre Martyr are one of the proofs of their extension beyond the Gulf of Mexico. There is also something characteristic in the form of the hair taken as a whole. Everyone knows the falsely called _woolly head_ of the Negro, which is covered with very short and crisp hair. The very long and harsh hair of yellow, American, and other populations, contrasts in a striking manner with the preceding. That of the white races, which is frequently curly, almost takes the mean between these two extremes. This general aspect ordinarily corresponds with the differences of structure and general form of the hair. Brown has already proved that a horizontal section of the hair varies from an elongated ellipse with the Negro, to a circle with the Red-Skin, and that the hair of the Anglo-Saxon is a mean between the two. Pruner Bey has resumed this study, and described the form of a horizontal section of the hair in several races belonging to the three fundamental types. He has proved that the elongated ellipse characterises Negro races in general, as well as the Hottentot-Bosjesman; that the oval forms belong essentially to Aryan populations; that more or less regularly circular forms characterise yellow, American, and other races, and that in this respect the allophylian white races (Basques) appear to resemble the preceding. Brown and Pruner Bey moreover agree in the statement that a mixture of forms is found upon the heads of half-breeds. Exactly the same often happens in the crossing of the merino with races of sheep with a coarse wool. I have hitherto only spoken of the characters furnished by the beard and the hair when grown freely. But it is well known that the love of adornment, one of the most characteristic instincts of man, endeavours to modify nature in these two directions. This results in characters, which are doubtless artificial, but which have sometimes a real value. This side of the question has often been attacked, and M. E. Cortambert has made it the object of a work, in which he has given a summary of the work of his predecessors in addition to his own.