134 . BECKHAM. [Vol. 1, 



the immense mass of facts going to show that "individual var- 

 iability is a general character of all common and widespread 

 species of animals or plants; and, further, that this varia- 

 bility extends, so far as we know, to every part and organ, 

 whether external or internal." ''^ 



If this be true, what is the difficulty in supposing that 

 the females have selected one ornamental variation rather than 

 another, and that, as the generations passed, this process being 

 cumulative, all the sexual color and ornament that we find in 

 nature have resulted? This supposition would at least explain 

 the facts. It is expressly to make clear why the ornamenta- 

 tion appears so frequently in certain tracts of the body that the 

 supporters of female selection have brought forward the in- 

 numerable instances of male display, and, at the risk of being 

 tedious, have pomted out that the ornaments are always well 

 in view of the female, and presumably for her benefit. 



When Mr. Wallace denied that the choice of the female 

 was influenced by ornamentation (not because this would not 

 explain the facts, but because he disbelieved in any such predi- 

 lection on her part), he was left without any explanation of the 

 very important fact that color and ornament in birds, insects 

 and spiders almost always appear in certain parts of the bodj'. 



The explanation which he now offers (which was sug- 

 gested to him by the theory of Mr. Tylor) is that color and ac- 

 cessory plumes are situated on surfaces where muscular and 

 nervous development is considerable and where functions 

 change ; and that this is in fact the cause of the ornamentation 

 and determines its distribution. He asserts that the develop- 

 ment of color and feather is proportional to that of muscle and 

 nerve, and if he can establish this conjunction he will go a 

 long way towards substituting his own theory for that of female 

 choice. 



In so complex a subject it is necessary, even at the risk of 

 being wearLsome, to analyze the steps of the argument into 

 their siinplest terms; and the more so because the force and 

 charm of Mr. Wallace's style sometimes carry the reader too 



* Darwinism, p. SJ. 



