614 ANATOMY OF VERTEBRATES. 



firmer nuclei, and, finally, become pressed into dry hard scales at 

 the periphery of the epiderm. Many of the deepest-seated and 

 first-formed cells contain coloured particles or pigment, consti- 

 tuting the ( rete mucosum,' or f malpighian layer,' fig. 484, d. 

 This pigment, combined with the cells constituting the hairs or 

 spines, gives the characteristic colour of the quadruped, and 

 seems to affect the derm itself. It rarely manifests, in Mam- 

 mals, the bright and pure colours noticed in the skin of Birds 

 (p. 231, vol. ii.); but to the face of certain baboons it may 

 give a red, blue, or violet tint. In quadrupeds with circum- 

 scribed patches of black hair a deposition of dark pigmentum 

 may be traced in the corium above the sheaths whence the black 

 hairs grow. The darker-coloured skin and hair is, as a rule in 

 Mammals, on the upper or more exposed surface of the body, 

 and the lighter-coloured pelt is below. But in the Ratel and 

 Skunk the ordinary arrangement of colours is reversed, the back 

 being light and the belly dark : the white bands of hair in the 

 Skunk are associated with a corresponding colour of the corium, 

 and are seen on the inner side of the dried pelt. In the human 

 subject the amount and colour of the subcuticular pigmental 

 cells relate, but not absolutely as regards existing continents and 

 peoples, to the degree of solar influence to which the skin is ex- 

 posed. A fair complexion and light hair do not characterise any 

 race indigenous to tropical and warmer temperate latitudes, but 

 are limited to cooler temperate and cold climes, which, from the 

 present excess of dry land in that hemisphere, are northern or 

 arctic. The continent of Europe, if the complexions of its peoples 

 be compared from Scandinavia to the Mediterranean, exemplifies 

 the progressive deepening of the tints of skin, hair, and eyes, as 

 the sun exerts more power. But the Asiatic part of the ' Old 

 World ' shows this relation in a minor degree. The aborigines 

 of Northern Asia to Kamtschatka are, like the Japanese, of a 

 brownish-yellow complexion : the same prevails through all the 

 latitudes of the vast Chinese Empire ; but the southern extensions 

 of that people into Cochin-China, Siam, and Burma, do show a 

 deeper brown. The Hindoos retain the same almost black tint over 

 a range of twenty- six degrees of latitude and twenty-four degrees 

 of longitude ; but these are tropical, or nearly so. The Malays of 

 the Indian Archipelago preserve the same deep brown tint over 

 eighteen degrees of latitude, reckoned from the equator north- 

 ward, and the tint would seem still to relate to such excess of 

 solar influence ; although the sway of other causes is exemplified 

 by the darker Mincopies, Cingalese, and Hindoos, under similar 



