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THE AMEBIC AN NATURALIST [Vol. XLIV 



males pay no attention to immature females, while they 

 do in L. scutulata. During the past summer I have seen 

 males courting- immature females in the attid Zygoballus 

 beltini, the thomisid Xysticus nervosus, and the drassid 

 Chiracanthium inclusum. 



In some species, as notably epeirids and lycosids, 

 jDregnant females are hostile to males. But I have seen 

 such females of Theridium tepidurionun and Phidippns 

 purpuratus receive males, and on one occasion a female 

 of Geotrecha pi >niaf a was interrupted several times during 

 her cocooning by embraces of a male. Males appear to 

 court any mature female, whether she be virgin or not. 



II. Senses Employed in Sexual Recognition and 

 Stimulation 



Here we have to consider briefly the roles of hearing, 

 touch, sight and smell. 



There is no good evidence that spiders possess hear- 

 ing, while the arguments of Wagner (1888) and espe- 

 cially the direct observations of Pritchett (1905, done 

 under my direction) speak almost conclusively against 

 such possession. Some spiders have stridulating organs, 

 and in certain species these are limited to the male 

 {Theridium, according to Westring), but no experi- 

 ment have been made to determine whether the spiders 

 react to the sounds produced thereby. I have recently 

 found in the drassid genus Geotrecha, where both sexes 

 possess a stridulating apparatus, the spiders do not in 

 any way indicate any perception of sound but perceive 

 each other solely by touch. It is then fairly firmly 

 established that the sexes do not recognize each other 

 by hearing. 



Touch is the dominant sense, and would appear to be 

 the especial function of the jointed spines. In nocturnal 

 species as well as in all snare-weavers it appears to be 

 the only sense of sex-recognition. 



Smell is possessed by spiders, but what organs sub- 



