142 PKOCEEDINGS OF THE ACADEMY OF [Jan., 



the males communicate signals to females, and are answered by them, 

 by pulls upon the web-lines connecting the two individuals. And 

 in some Agalenidce, as Tegenaria derhami, the males approach the 

 females very slowly at first, tapping upon the horizontal sheet of the 

 web with their palpi and first pair of legs. But such motions on the 

 part of the male should be interpreted rather as signals of the male 

 to determine the sex and the degree of eagerness in his partner, than 

 as a courtship proper. Similar are the approaches of the Dictynids. 

 The male in the Thomisidcc {Xysticiis stomachosus) makes no prelimi- 

 nary motions whatsoever, but as soon as he touches the female seeks 

 to immediately mount upon her back. 



The question of the psychology of courtship among animals is a 

 very great one. How, in the first place, does one sex recognize the 

 other as such? One of the greatest wonders in the study of animal 

 habits, though it is so general that its strangeness is overlooked, is 

 that one individual, before it has once experienced an act of union with 

 an individual of the other sex, has the sense that that other individual 

 can gratify its desire, and can unerringly perform that act. In the 

 spider it is still more remarkable, for the male has first to perform the 

 act of charging the palpi with sperm. This is no act of mere automa- 

 tism ; here the animal shows most truly that it cannot be compared with 

 a machine. ''Gonotropism" is a mere name and does not explain nor 

 classify the process. Broad questions like this one must be elucidated 

 before we can hope for any adequate explanation of courtship, a per- 

 formance of secondary importance, and consequently I would call 

 attention here merely to certain peculiarities in the courtship of spiders. 



In the first place, courtship is primarily an expression of eagerness 

 upon the part of the male. The male is mature, and the recognition of 

 the opposite sex in a state of maturity also stimulates him to the 

 excess of desire. It may be at first a mental state, which then reflects 

 upon the organization and perturbs the latter. Great excitement finds 

 expression in muscular activity, and hence the peculiar, exaggerated 

 movements corresponding to an abnormal state of stimulation. In 

 some animals the male, once so excited, rushes at the female; in other 

 he does not do so immediately, but goes through a preliminary set of 

 motions, which may be termed courtship when they are regular and 

 more or less rhythmical. Now in the case of the araneids, whj^ does 

 not the male immediately hasten to the female, since by so doing he 

 would most quickly gratify his desire? Several answers might be 

 suggested: (1) that the male seeks to reach the highest pitch of ex- 

 citement, or waits until that state is reached, before approaching the 



