SEXUAL SELECTION 645 



doubtedly been obscurely colored for the sake of protec- 

 tion. In some instances the upper exposed surface of the 

 plumage has been thus colored in both sexes, while the 

 lower surface in the males alone has been variously orna- 

 mented through sexual selection. Finally, from the facts 

 given in these four chapters, we may conclude that weapons 

 for battle, organs for producing sound, ornaments of many 

 kinds, bright and conspicuous colors, have generally been 

 acquired by the males through variation and sexual selec- 

 tion, and have been transmitted in various ways according 

 to the several laws of inheritance — the females and tha 

 young being left comparatively but little modified." 



" I am greatly indebted to the Idndneaa of Mr. Sclater for having looked 

 «ver these four chapters on birds, and the two following ones on mammals. 

 In this way I have been saved from making mistakes about the names of tha 

 Bpecies, and from statiag anything as a fact which is known to this distin- 

 guished naturalist to be erroneous. But of course he is not at all answerabla 

 for the accuracy of the statements quoted by me from various authorities. 



Descent— Vol. n.— 10 



