THE REDISCOVERED COUNTRY 339 



reverse is the case. On both plains there are, however, 

 plenty of both species. I should say the lion population 

 is about equally divided. The disparity of numbers, in my 

 mind, is not due to lion killing, but to some as yet unex- 

 plained breeding dissimilarity due to some as yet un- 

 described advantage or disadvantage to one or the other 

 species. 



Of course it may be superficially argued that if this is 

 true, it should also follow that beasts not countershaded 

 should be fewer in numbers than the others, because more 

 of them are killed. But this might, and probably does, 

 depend on other factors — how prolific are their breeding 

 habits, tendency to infant mortality from other causes, etc., 

 etc. 



In short, countershading seems to me to be a principle 

 that on broad general lines works out. It does not always 

 work out, and its possession would not for a moment conceal 

 any individual from me — let alone a native or a lion — if I 

 were looking for him. But it might cause me to pass him 

 by for a more conspicuous animal if I were just after meat 

 in general. That would be a chance; and of a great ag- 

 gregation of chances is made the fate or the evolution of 

 species, provided, of course, that the theory of evolution or 

 survival is accepted. 



2. The theory of night blending: This, as an expla- 

 nation of white tails, and generally white upper parts, seems 

 to me a mistake. Mr. Thayer's optical contention is un- 

 doubtedly true, as it affects human eyes. A white object, 

 at a reasonable distance, is in many circumstances — but by 

 no means always — less visible at night than a dark object. 



