AND COLOUR OF THE IRIS. 265 



latter organ, and partly in the cellalar texture which uuites 

 it to the subjacent parts. This bulb consists of a dense ex- 

 ternal covering, in which the tubular root of the hair, and a 

 conical vascular pulp, by which that root is secreted, are 

 contained ^. The vascular body adds the new matter to 

 the root of the hair, which is elongated by these additions, 

 in the sauie way as the nail grows by its root. The conical 

 vascular pulp, and the hollow of the hair in which it is lodged, 

 are easily seen in the larger examples, which the whiskers of 

 many mammalia afford. The precise relations of the cuticle 

 and rete mucosum to the hair have not been ascertained ; 

 it is not settled whether these coverings are simply perfo- 

 rated, or whether productions of them are continued over 

 the hairs. It is, however, clear that the colouring principle 

 is of a common nature in the skin and hair ; and, moreover, 

 that there is a connexion between them in texture. 



The colourless Albino has a soft white hair. In the 

 first or white variety of the human species, every gradation 

 from the fair to the dark is accompanied by correspondent 

 alterations in the tint of the hair. This is true, not only of 

 nations, but of individuals, in the white races. A light 

 complexion and thin skin are accompanied with delicate fair 

 or red hair; a dark one and thick skin with black hair, 

 almost invariably, even in individuals of the same family ; 

 a difference which, according to the philosophy of some 

 writers, would be a sufficient ground for classing them in 

 distinct species. 



The four coloured varieties of men have black hair, 

 which is always stronger and coarser in texture than in the 

 whites. This difference is particularly noticed by the Chi- 

 nese, who contemptuously compare the hair of Europeans 

 to the soft fur of the smaller animals. In Negroes, native 

 Americans, and New Zealanders, I have found the texture 

 much stronger than in the darkest Europeans. A striking 



* See the article h^ir in Comparative Anatoviij, in the Cyclopsedia of Dr. 

 Kees ; contributed by Dr. Macartney, Professor of Anatomy in Trinity 

 College, Dublin. 



