CHAP. X ] SEXUAL SELECTION. 305 



But if sexual character is here allowed to be due to some 

 other cause, why is it not so due elsewhere also ? The question 

 suggests itself after reading the following sentence : 



&quot; Many corals, sea-anemones, some jelly-fishes, Planarize, Ascidians, 

 starfishes, Echini, &c.,&quot; &quot; are ornamented with the most brilliant tints, 

 or are shaded and striped in an elegant manner ;&quot; yet here &quot; we may 

 conclude that such colours have not been acquired through sexual selec 

 tion.&quot; -Vol. i. p. 321. 



The uncertainty which besets these speculations of Mr. 

 Darwin is evident at every turn. What, at first, 

 could be thought a better instance of sexual selec 

 tion than the light of the glowworm, exhibited to attract her 

 mate ? Yet the discovery of luminous Iarva3, which of course 

 have no sexual action, leads Mr. Darwin to observe that &quot; It 

 is very doubtful whether the primary use of the light is to 

 guide the male to the female &quot; (vol. i. p. 345). Again, as to 

 certain British field-bugs, he says, &quot; If in any species the males 

 had differed from the females in an analogous manner, we might 

 have been justified in attributing such conspicuous colours to 

 sexual selection with transference to both sexes&quot; (vol. i. 

 p. 350). As to the stridulating noises of insects (which is 

 assumed to be the result of sexual selection), Mr. Darwin 

 remarks of a certain Neuropteron : &quot;It is rather surprising that 

 both sexes should have the power of stridulating, as the male 

 is winged and the female wingless &quot; (vol. i. p. 366) ; and he 

 is again surprised to find that this power is not a sexual 

 character in many (Joleoptera (vol. i. p. 382), i.e., not different 

 in the two sexes. 



Moths and butterflies, however, are the insects which Mr. 

 Darwin treats of at the greatest length in support of sexual 

 selection. Yet even here he supplies us with a thorough 

 demonstration that in certain cases beauty does not charm 

 the female. He tells us : 



&quot; Some facts, however, are opposed to the belief that female butter 

 flies prefer the more beautiful males ; thus, as I have been assured by 

 several observers, fresh females may frequently be seen paired with 

 battered, faded, or dingy males.&quot; Vol. i. p. 400. 



- . X 



