58 THE GENETIC AND THE OPERATIVE EVIDENCE 



"We may fairly say, then, that the humming-birds completely refute the 

 proposition that there is any relation between the development of color and 

 accessory plumes and 'surfaces where muscular and nervous development is 

 considerable.' m 



What is true for birds is even more obvious for spiders where the 

 special ornaments are not confined to parts of the body with high 

 muscular development, etc. The writers make the very pertinent 

 criticism that while Wallace objects to assuming the emotional states 

 in females, he is less careful in regard to the males' emotions when he 

 speaks of the display "under the influence of jealousy or sexual excite- 

 ment The males, in their rivalry with each other, would see 



what plumes were most effective; and each would endeavor to excel his 

 enemy as far as voluntary exertion would enable him." 2 



"If the males have so complex an emotion as jealousy, and further, if they 

 are conscious of the value of the plumes, may it not be asked why the female is 

 unable to ' see what plumes are most effective?' The mental state in the male 

 is without meaning unless we suppose the female to be affected and pleased." 

 (Peckham, loc. tit., p. 144.) 



In regard to another interpretation of the courtship, the Peckhams 

 point out: 



"Mr. Pocock has suggested that the attitude of observant interest on the 

 part of the female spider might be taken to indicate that she was preparing to 

 spring upon her mate and devour him; or that it might simply mean that she 

 was warily guarding herself from his approach. Neither of these suppositions 

 is admissible. In some species the male is not attacked by the female, and 

 when she does wish, as frequently happens, either to avoid or to destroy him, 

 her attitude is totally different. In the former case she turns about and runs 

 rapidly away, or suspends herself by a thread of web. In the second, there is a 

 contraction of all the muscles, the legs are drawn together, and in this crouch- 

 ing position she creeps slowly toward him, as she might if he were a fly, only 

 with something more malignant in her aspect. When she takes this stand the 

 male incontinently flees. When, on the contrary, the female is interested in 

 the male display, she seems perfectly absorbed in watching him, the muscles 

 are all relaxed, unconscious of herself she directs her glance now here, now 

 there, as he moves about; as he continues his mad antics, her appearance gives 

 every indication of pleasurable excitement, and as he comes closer and closer, 

 she yields herself to the impulses which he has awakened in her, and, as in 

 pulex, joins in his dance and whirls around and around as though intoxicated. 

 We claim, then, to have completely answered Mr. Wallace's first objection." 

 (Peckham, loc. cit., pp. 145, 146.) 



Finally, in regard to the specific character of the display of the 

 males, the Peckhams make the following significant statement : 



1 Among the most remarkable of this wonderful family are the nine species of coquettes (Loph- 

 orois), which have elongated feathers, with metallic tips, springing from the sides of the neck; 

 some have also beautiful crests. (George W. and Elizabeth G. Peckham., Additional Observa- 

 tions on Sexual Selection in Spiders of the Family Attidae., Nat. Hist. Soc. of Wisconsin, 1889, 

 vol. I, pp. 141, 142.) 



1 Tropical Nature, p. 210. The italics are ours. 



