6 PROCEEDINGS OF THE CANADIAN INSTITUTE. \ \, 



Another explanation of some of these facts, that possesses a certain 

 degree of probability, is, that difference of colour in the same country . 

 is due to mode of life. It may be maintained that the Samangs of 

 Malaca, and the Aetas of the Philippine Islands are darker than 

 the other inhabitants, because the poorness of their dwellings, and 

 their consequent practically constant exposure to sun or wind, renders- 

 it an advantage for them to be dark. 



Another explanation to which I shall make reference later, is that 

 humidity is probably not the sole climatic influence that operates. 



I may say here that I do not attach importance to the direct in- 

 fluence of climatic conditions. It is, indeed, a matter of common 

 observation that these produce considerable effects on the individual 1 . 

 Pruner-Bey, for example, states that he has noticed that " the Euro- 

 pean acclimated in Egypt acquires after some time a tawny skin,, 

 and in Abyssinia a bronzed skin ; he becomes pallid on the coast of 

 Arabia, cachectic white in Syria, clear brown in the deserts of Arabia, 

 and ruddy in the Syrian mountains." But there is no proof that 

 these cutaneous changes are inherited. If, however, it can be shown 

 that a particular kind of skin is better than others for resisting the 

 deleterious influences of a given climate, it stands to reason that 

 those members of a race whose skins vary in the direction of this 

 type, will, in each generation have the best chance of surviving and 

 begetting children, and that by the continued increment of successive 

 variations in the same direction, the skin and the climate will ulti- 

 mately be brought into accord. 



The skin consists of two layers : the inner, dense and fibrous, 

 furnished with blood vessels and nerves, called the derma or true 

 skin ; the outer, horny, nerveless and bloodless, called the epidermis, 

 cuticle, or scarf-skin. The cells which compose the latter originate 

 in the rete Malpighii, its lowest part, are gradually forced outward 

 by new cells and finally exfoliate. In some of these epidermic cells 

 a pigment is found which varies in different races, but always con- 

 tains a yellow element. The hue of the skin does not depend on 

 this colouring matter alone, but is a compound effect resulting from 

 the white of the dermis, the red of the blood in the minute vessels 

 near the surface, the colour and quantity of the pigment, and the 

 thickness of the cuticle. Where the cuticle is thick, the colour of the 

 pigment will predominate over the other elements on account of the 

 greater depth of pigment-cells. Where it is thin, and the colouring 



