148 AFRICAN GAME ANIMALS 



increase in the brain power or sharpness of senses of the 

 adults has caused the coloration to become a negligible factor 

 in the animal's success in life. But it must mean that the 

 coloration of the adults of the present day has not been pro- 

 duced by natural selection for purposes of concealment. 



In sum, natural selection, operating with concealing 

 coloration as a survival factor, has played a wholly minor 

 part in developing the coloration of the higher vertebrates. 

 In the vast majority of cases it has certainly had no part in 

 originating the coloration; in a very large number, probably 

 a considerable majority, of cases it has certainly had no 

 effect even in preserving the coloration when produced. 

 It is possible, but not certain, nor even probable, that in a 

 very few cases it has produced the precise existing colora- 

 tion; it is probable that in a few cases it has preserved the 

 precise existing coloration after other factors have produced 

 it. It is well-nigh certain that in a number of cases, much 

 less than a majority, it has had a very real effect, not by 

 producing or preserving certain definite patterns or tints, 

 but by setting wide limits of variation which these patterns 

 and tints may not transgress. 



As far as our observations go, in the very limited field 

 they cover, they support Mivart's contention that the chief 

 part played by natural selection in organic evolution is the 

 part of a pruning-knife. As for asserting that as yet there 

 is warrant in dogmatizing about the origin of species, and 

 about evolution itself — why we are hardly on the threshold 

 of the matter. 



