GENERAL SUMMARY AND CONCLUSION. 701 



I am aware that the conclusions arrived at in tliis work 

 will be denounced by some as highly irreligious; but he 

 who denounces them is bound to show why it is more irre- 

 ligious to explain the origin of man as a distinct species by 

 descent from some lower form, through the laws of varia- 

 tion and natural selection, than to explain the birth of the 

 individual through the laws of ordinary reproduction. 

 The birth both of the species and of the individual are equally 

 parts of that grand sequence pf events, which our minds 

 refuse to accept as the result of blind chance. The under- 

 standing revolts at such a conclusion, whether or not we 

 are able to believe that every slight variation of structure, 

 the union of each pair in marriage, the dissemination of 

 each seed, and other such events have all been ordained for 

 some^ecial purpose. 



Sexual selection has been treated at great length in this 

 work; for, as I have attempted to show, it has played an 

 imptt;tant part in the history of the organic world. I am 

 aware that much remains doubtful, but I have endeavored 

 to give a fair view of the whole case. In the lower divis- 

 ions of the animal kingdom sexual selection seems to have 

 done nothing; such animals are often affixed for life to the 

 same spot, or have the sexes combined in the same indi- 

 vidual, or, what is still more important, their perceptive and 

 intellectual faculties are not sufficiently advanced to allow 

 of the feelings of love and jealousy, or of the exertion of 

 choice. When, however, we come to the Arthropoda and 

 Vertebrata, even to the lowest classes in these two great 

 sub-kingdoms, sexual selection has effected much. 



In the several great classes of the animal kingdom in 

 mammals, birds, reptiles, fishes, insects and even crusta- 

 ceans the differences between the sexes follow nearly the 

 same rules. The males are almost always the wooers; and 

 they alone are armed with special weapons for fighting with 

 their rivals. They are generally stronger and larger than 

 the females, and are endowed with the requisite qualities 

 of courage and pugnacity. They are provided, either 

 exclusively or in a much higher degree than the females, 

 with organs for vocal or instrumental music, and with 

 odoriferous glands. They are ornamented with infinitely 

 diversified appendages, and with the most brilliant or con- 

 spicuous colors, often arranged in elegant patterns, while 



