MY SOMALI BOOK 217 



therefore beneficial to tlie species, the new protective 

 colouring tends to be preserved and rendered permanent 

 by the agency of natural selection. 



In this connection I cannot do better than quote 

 from an interesting paper on the subject by Mr. C. E. C. 

 Fischer, which appeared not long ago in the Journal of 

 the Bomba}^ Natural History Society, vol. xix. : "It 

 is quite possible that environment has some influence 

 on the colouration of animals (though that has to be 

 proved as well as the exact agency through which it 

 acts) ; but this in no way affects the theory of pro- 

 tective colouration, rather the contrary. Every one 

 will admit that if it is environment that influences 

 colouration, it must do so in a great variety of shades 

 to account for the great differences in the colour of 

 animals inhabiting the same locality, e.g. tiger, sambar, 

 sloth bear, bison, etc., in India ; and the divergence 

 is still more striking in South Africa. 



** This being so, then either all animals (in similar 

 surroundings) under this influence should eventually 

 assume the same coats, or else external specific features 

 must tend to disappear, as there is nothing to fix the 

 colour, which may at any time be gradually changed 

 to any of the other colours brought about by the 

 particular environment. 



'' We here come to the clou : there must be some 

 force or influence to fix a particular colour, and we have 

 that agency in natural selection." 



Now I think Mr. Selous makes it clear that he has 

 no idea of rejecting Darwin's general principle of the 

 survival of the fittest by means of natural selection. 

 It is of the essence of Darwinism that all variations in 



