Chap. XVIII ] 



EQUAL TRANSMISSION. 



285 



with snow, the pale winter coats would probably be ren- 

 dered, through natural selection, whiter and whiter by de- 

 grees, until they become as white as snow. 



Although we must admit that many quadrupeds have 



Fig. 68.— Tragelaphus Rcriptus, male (from the Knowsley Menagerie). 



received their present tints as a protection, yet with a host 

 of species the colors are far too conspicuous and too sin- 

 gularly arranged to allow us to suppose that they serve 

 for this purpose. We may take as an illustration certain 

 antelopes : when we see that the square white patch on 



