62 AFRICAN GAME ANIMALS 



motionless and trusting to concealment. When it runs it 

 hitches its skin so as to bring the white of the belly up on 

 the side toward its disturber — a most remarkable example 

 of seemingly purposeful advertising coloration. 



So much for recognition marks. But by the ultra nat- 

 ural-selection men the chief stress is always laid on conceal- 

 ing coloration. Instead of treating concealing coloration 

 as something which is sometimes present and sometimes 

 absent, which is sometimes useful and sometimes not — in 

 other words, instead of treating it from the scientific stand- 

 point of the observer who prefers rather unsatisfactory and 

 partial truths to brilliant and comprehensive falsehoods — 

 men like Professor Poulton and, above all, Mr. Thayer treat 

 the extreme neo-Darwinian theory of protective or con- 

 cealing coloration as a law of nature. It is nothing of the 

 sort. It is at best, as Dewar and Finn point out, a work- 

 ing hypothesis which is useful as throwing light on certain 

 phenomena, and which does apply in a large number of 

 cases. It breaks down if the attempt is made to apply it 

 universally or nearly universally, and is demonstrably false 

 as applied to all sexes and ages of many thousands of species 

 of the higher vertebrates, mammals, birds, and even reptiles 

 (to speak only of species which we have personally studied). 

 Professor Poulton has conducted a number of experiments 

 under highly artificial conditions, and has drawn certain 

 conclusions, partly from these experiments, but much more 

 largely from what can hardly be called anything except 

 closet theorizing. Mr. McAtee, in the paper quoted above, 

 has shown why these particular experiments and conclu- 

 sions have small value; this being done as an incident to 

 showing why most experiments under artificial conditions 

 have small value. 



