No. 519] THE COURTSHIP OF A RAX FADS 173 



markings. These differences are so pronounced in the 

 attids that in many cases the species is known only by 

 one of the sexes. We have previously seen that conscious 

 esthetic choice by the female probably does not account 

 for such male characters, that they are, accordingly, 

 probably not due to sexual selection. These characters 

 of the males may be most readily explained as being con- 

 served by simple natural selection. Peculiar male orna- 

 mentation would be selected because it insures quicker 

 sex-recognition, therefore prompter mating. The male is 

 thereby more surely accepted by the female, not selected 

 by her in the sense of Darwin. The process is much 

 more an announcement of sex by the male than a choice by 

 the female, and results in the female accepting the sex 

 rather than the individual. There is no reason to sup- 

 pose the female spider is actuated esthetically, while we 

 do know she is actuated sexually— in some cases quite as 

 much as the male is. There is no need of calling in any 

 other factor than natural selection. 



Whether such ornamental male characters, which stim- 

 ulate the visual sense of the female, subserve sex recog- 

 nition rather than sex stimulation we are hardly able to 

 decide in the absence of any thorough analysis of the 

 psychical states of spiders. But probably a female would 

 first have to recognize a male as a male before she became 

 sexually aroused by him, and for this reason male orna- 

 mentation would seem to be primarily to insure sex-recog- 

 nition rather than sex-stimulation. 



In opposition to the views of Wallace (1889) the Peck- 

 hams (1890) have correctly argued that the ornamentation 

 of male spiders is not due to any " higher degree of vital- 

 ity" of the males, for the female seems to be in all re- 

 spects fully as active as the male, and at maturity even 

 more active. The same objection may be made against 

 the concept of Geddes and Thomson (1897) with regard to 

 differences of the sexes. 



The Peckhams have found in the attids, in agreement 

 with Darwin's conclusions for birds, that: (a) when the 

 adult male is more conspicuous than the adult female, the 



