88 CALIFORNIA ACADEMY OF SCIENCES. 



highly probable, then, of course, every bird does not 

 find a mate, and Mr. Wallace's objection is invalidated. 

 Prof, and Mrs. Peckham have shown that among the 

 Attidce every male does not get a mate. They say: *" In 

 spiders, as the females gradually become adults, they 

 have a choice from among a number of males, as these 

 mature several days earlier. The males will pair as often 

 as they have the opportunity, and as the mating season 

 lasts for two or three weeks, the more brilliant males may 

 easily be selected again and again." 



Of considerable significance as showing the unsettled 

 state of scientific opinion upon this difficult question, is 

 the fact that two eminent English naturalists have each 

 just published a work in which the subject is discussed, 

 and have arrived at directly opposite conclusions. Prof. 

 Frank E. Beddard, in his book entitled Animal Color- 

 ation, concludes that sexual selection, if operative at all, 

 is a very insignificant factor, while Prof. George J. 

 Romanes, in the first volume of the series on Darwin and 

 After Darwin, writes to the contrary in the following 

 emphatic sentence: f "And, as regards the particular 

 case now before us, I think I have shown, as far as space 

 will permit, that in the phenomena of decorative colour- 

 ing (as distinguished from merely brilliant colouring), 

 of melodious song (as distinguished from merely tune- 

 less cries), of enormous arborescent antlers (as distin- 

 guished from merely offensive weapons), and so forth 

 I say that in all these phenomena we have phenomena 

 which cannot possibly be explained by the theory of 

 natural selection; and, further, that if they are to be ex- 

 plained at all, this can only be done, so far as we can at 

 present see, by Mr. Darwin's supplementary theory of 

 sexual selection." Inasmuch as these two scientists have 



*1. c., p. 60. 

 t p. 400. 



