92 CALIFORNIA ACADEMY OF SCIENCES. 



leave offspring, because from their very advantages over 

 the females in point of numbers and strength, they 

 would prevent them from rearing their young. Conse- 

 quently these unornamented and inconspicuous males 

 would leave fewer offspring than the conspicuous males 

 which were fewer in numbers. The survival of the fittest, 

 then, should be regarded in the long run as the survival 

 of the individuals best fitted to leave offspring. 



And now it may be well to enquire how this theory 

 might be made to support sexual selection instead of 

 opposing it, as Prof. Beddard intended it should. A 

 very weighty objection to sexual selection has been 

 raised by Mr. Wallace, viz., that even admitting the fact 

 of selection on the part of the female bird its influence 

 would be entirely neutralized by natural selection, for if 

 these ornaments were developed solely for the sake of 

 beauty, the individuals possessing such charms would 

 be at a disadvantage in the struggle for existence, and 

 perish. If the paradox can be demonstrated, on the 

 contrary, that these disadvantageous appendages which 

 have been acquired for the purpose of adornment, are 

 in reality an advantage, this difficulty is entirely done 

 away with. 



Prof. Romanes does not consider Mr. Wallace's objec- 

 tions in great detail, but takes issue with him on the 

 leading points in question. He says:* " There is no 

 conceivable reason why mere brilliancy of color, as an 

 accidental concomitant of general vigor, should have 

 run into so extraordinary, so elaborate, and so beautiful a 

 design of colors. Moreover, this design is only unfolded 

 when the tail is erected, and the tail is not erected in 

 battle (as Mr. Wallace's theory of the erectile function 

 in feathers would require), but in courtship; obviously, 

 therefore, the purpose of the pattern, so to speak, is cor- 



1. c., pp. 394-395. 



