Chap. XXL] AND CONCLUDING REMARKS. 379 



I am aware that much remains doubtful, but I have 

 endeavored to give a fair view of the whole case. In the 

 lower divisions 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 two sexes 

 combined in the same individual, or, what is still more im- 

 portant, 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 ; and it deserves notice that 

 we here find the intellectual faculties developed, but in 

 two very distinct lines, to the highest standard, namely, 

 in the Hymenoptera (ants, bees, etc.) among the Arthro- 

 poda, and in the Mammalia, including man, among the 

 Vertebrata. 



In the most distinct classes of the animal kingdom, 

 with mammals, birds, reptiles, fishes, insects, and even 

 crustaceans, the differences between the sexes follow al- 

 most exactly 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 pug- 

 nacity. They are provided, either exclusively or in a 

 much higher degree than the females, with organs for pro- 

 ducing vocal or instrumental music, and with odoriferous 

 glands. They are ornamented with infinitely-diversified 

 appendages, and with the most brilliant or conspicuous 

 colors, often arranged in elegant patterns, while the fe- 

 males are left unadorned. When the sexes differ in more 

 important structures, it is the male which is provided with 

 special sense-organs for discovering the female, with loco- 

 motive organs for reaching her, and often with prehensile 



