THE SKIN. 67 



we can observe the pigment, or colouring matter, which ren- 

 ders an animal's skin black. The pigment is lodged in the 

 form of dark granules in the cuticular cells. 



Not only does the cuticle penetrate between the folds and 

 prominences or papillae of the skin, but tubular prolonga- 

 tions enter the ducts of the glands of the skin and the hair- 

 follicles, so that the whole surface of the body is effectually 

 enclosed by the cuticle. 



Speaking of the pigment of the skin, Mr Erasmus 

 Wilson says : " Colour of the skin has reference to energy in 

 its action; thus, in the tropics, where light and heat are in 

 excess, and the skin is stimulated by these agents to vigorous 

 action, colour is abundant and intense; while in the frigid 

 north, where both are wanting, the lungs, the liver, and the 

 kidneys relieve the skin of part of its duties. The same 

 observation relates to summer and winter: under the en- 

 livening warmth of the summer sun, with its flood of light, 

 exposed parts of the fairest skin become brown; that is, 

 their pigment-forming energy is increased. But the winter's 

 scarf-skin is white and pigmentless, and restores the fair com- 

 plexion when the summer's scarf is worn away. The law of 

 colour, as relates to man, is, therefore, the same as that which 

 sheds its influence over the vegetable world: the winter's 

 flower and the first blossom of spring are cold and pigment- 

 less, while the warm hues of the dahlia are borrowed from 

 the bright sun of summer and early autumn." 



The true skin cutis vera, corium, or dermis is a denselayer 

 of connective or delicate areolar tissue, highly endowed with 

 the properties of feeling and secretion, and serves as the bed 

 or matrix for the hairs, &c. Its structure is continuous with 

 all tissues beneath it through the connective-tissue. It is 

 firmly attached over the trunk, neck, and face in quadrupeds, 

 to a skin muscle, panniculus carnosus, which may be seen 



