PROTECTIVE RESEMBLANCES, AND MIMICRY 223 



are explained by some naturalists the brilliant plumage of 

 the male birds, as in the case of the bird-of-paradise and 

 the pheasants. Or they may serve for recognition charac- 

 ters, enabling the individuals of a band of animals readily 

 to recognize their companions ; the conspicuous whiteness 

 of the short tail of the antelopes and cotton-tail rabbits, 

 the black tail of the black-tail deer, and the white tail- 

 feathers of the meadow-lark, are explained by many natu- 

 ralists on this ground. Eecognition marks of this type 

 are especially numerous among the birds, hardly a species 

 being without one or more of them, if their meaning is cor- 

 rectly interpreted. The white color of arctic animals may 

 be useful not alone in rendering them inconspicuous, but 

 may serve also a direct physiological function in preventing 

 the loss of heat from the body by radiation. And the dark 

 colors of animals may be of value to them in absorbing heat 

 rays and thus helping them to keep warm. But " by far 

 the most widespread use of color is to assist an animal in 

 escaping from its enemies or in capturing its prey." 



The colors of an animal may indeed not be useful to 

 it at all. Many color patterns exist on present-day birds 

 simply because, preserved by heredity, they are handed 

 down by their ancestors, to whom, under different condi- 

 tions of life, they may have been of direct use. For the 

 most part, however, we can look on the varied colors and 

 the striking patterns exhibited by animals as being in some 

 way or another of real use and value. We can enjoy the 

 exquisite coloration of the wings of a butterfly none the 

 less, however, because we know that these beautiful colors 

 and their arrangement tend to preserve the life of the 

 dainty creature, and have been produced by the operation 

 of fixed laws of Nature working through the ages. 



