187 



antennae, causing a constant movement of air between their 

 finest pectinations, would facilitate the action of no known sense 

 except the sense of smell. 



If then the male is sexually excited and guided to his mate by 

 a sense of smell located in the antenna3, the final act of copula- 

 tion must be effected by some other sense, as these organs are 

 never directly applied to the genitals of the female. This is 

 the case. The male liglits upon the female's body, and gropes 

 around with his claspers, until he discovers the projecting horny 

 ring fitted for his grasp. A sexually excited male will endeavor 

 to copulate with a dead female, another male, or even a piece 

 of cotton twisted into the shape of the body. In this last ex 

 periment every precaution was taken to prevent the faintest 

 smell of the female about the cotton. 



If the previous conclusions are correct, it would logically 

 follow that an insect so intensely sexually excited as a male C. 

 prometliea would retain the excitement for a short time after the 

 sensation causing the excitement had ceased. The nerve cen- 

 tres would remain in the condition produced by the action of 

 the volatile substance on the nerves of the aritennai after the 

 smell itself had stopped. In fact, he should strive to effect 

 copulation even after the antennjB are removed. As a conclusion 

 to this season's investigations, I put this deduction to an exper- 

 imental test. An attractive female was held by the wings in the 

 open air. A male soon approached. As he alighted on her 

 body he was caught, the antennae were removed, and he 

 was instantly replaced in his former position. Immediately 

 he began groping around with his claspers, and soon copu- 

 lated. After a few seconds, no longer feeling the stimulus 

 through his antennae, he lost his desire, loosed his hold, and, after 

 again feeling around with his claspers, fiew away, a])parently as 

 Avell as ever. To make snre that the fault was not with the 

 female, I allowed the next male who approached to copulate, 

 and he was perfectly successful. 



From these observations it seems fair to conclude that the 

 virgin female exhales a volatile substance, which, acting on the 

 antennae of the male, produces sexual desire, and prompts him 

 to fly against the wind ; that this exhalation is principally from 



