No. 1.] SEXUAL SELECTION IN SPIDERS. 9 



ser Bird of Paradise, which he took with him to England, as 

 though he kept them together.' If the trait of pugnacity is 

 so closely related to brilliant ornamentation in the humming- 

 birds, why should it not not be so in the birds of paradise ? 

 And why do we find brilliant color in many birds that have no 

 more — indeed rather less — vigor than the soberly dressed birds 

 of prey? Since, of all living naturalists, Mr. Wallace is un- 

 doubtedly the most competent to discuss this theory of the 

 correlation of great vitality and bright color, it is surprising 

 that he can find so little evidence in its favor. 



Perhaps the most difficult fact to reconcile with the theory 

 is the absence of ornamentation and bright color in the bats. 

 They have wide expanse of integument, and great activity, 

 the conditions specified by Mr. Wallace for the development of 

 gaudy pigment, and nothing, apparently, in their habits to keep 

 it down ; but, except in the frugivorous bats, we find little dif- 

 ference between the sexes, nor is there any appreciable ap- 

 proach to bright colors. As Darwin remarks, it deserves atten- 

 tion as bearing on the question whether bright colors are serv- 

 iceable to male animals from being ornamental, that only in 

 frugivorous bats is the sense of sight well developed, and it is 

 only in this group that we find any color.^ 



In the Araneides the great number of species and the wide 

 differences between the several groups in habits and in amount 

 of ornamentation, offer unusual facilities for testing Wallace's 

 two theories of sexual color. 



There is a common impression that among spiders 

 there is little development of ornamentation, and that 

 they are, as a rule, inconspicuous and dull. This is far from 

 being true. Wallace, in his Tropical Nature, says : " The 

 small jumping spiders are also noticeable from their im- 

 mense numbers, variety and beauty. They frequent foliage and 

 flowers, running about actively in pursuit of small insects ; and 

 many of them are so exquisitely colored as to "resemble jewels 



iLoc. cit., p. 667. 



2 Descent of Man, p. 634. 



