COLORATION 137 



cumstances this countershading tends toward the conceal- 

 ment of a few mammals and birds, but as regards the 

 immense majority of mammals and birds so many other 

 elements enter into the problem that the working of the 

 law is negligible from the standpoint of practical effect. 



There remains the general question of concealing color- 

 ation as a survival factor produced through natural selec- 

 tion in the case of birds and mammals. The first and most 

 important point to remember is that, as regards the im- 

 mense majority of birds and mammals, the prime factors in 

 securing their safety are habit, if they do not trust to con- 

 cealment, and habit and cover if they do trust to conceal- 

 ment. Most landscapes in nature are so varied and ac- 

 cidented and contain such myriads of differently shaped 

 objects, such a multitude of vistas superimposed and inter- 

 lacing, and such a well-nigh infinite variety of colors, lights, 

 and shades, as to make it extremely diflficult to pick out 

 any one object of any color. This is why a thick and high 

 forest, especially a tropical forest, offers such extraordinary 

 protection to all its inhabitants that no coloration scheme 

 among the adults of these inhabitants seems to be of any 

 consequence. This is why it is so hard in a varied moun- 

 tain or hill landscape to pick out a pika in a mass of slide- 

 rock, even though he can be heard uttering his querulous 

 note; or to see a marmot feeding; or a mountain-sheep ly- 

 ing down; or a klipspringer going about his daily business. 



As regards the big game of Africa and America, the 

 effect of the coloration, whether concealing or revealing, is 

 almost or quite negligible as far as the animals' enemies or 

 the other individuals of the species are concerned. Some 

 of them have a coloration which may legitimately be called 



