"JHEADVAKCEHJENTOFSCJEW 



PSYCHE. 



ORGAN OF THE CAMBRIDGE ENTOMOLOGICAL CLUB 

 Edited by george dimmock and b. pickman jiann. 



Vol II.] Cambridge, Mass., March- April, 1877. [Nos. 35-36. 

 Experiments on the Vitality of Insects. 



The following experiments are given just as recorded in my 

 note book on the spot, and may give a rough idea of the rela- 

 tive vitality of a few insects of different orders. 



PoUstes pallipes St. Fargeau. A male was beheaded at four 

 in the afternoon. He was as lively as ever, with the peculiar 

 motions of the species, at eight in the evening of the same day. 



From another male I removed the abdomen at four in the 

 afternoon. Five different times within five minutes after the 

 operation he lapped moistened sugar, as if nothing had hap- 

 pened. After taking food he cleaned his legs with his maxillse 

 several times. In twenty minutes he was again fed ; a drop of 

 dissolved sugar being placed near, but not touching his mouth- 

 parts ; he protruded his labium at once, and lapped the sugar 

 vigorously, in the usual manner. In forty minutes he fed 

 ao-ain, and in three hours and a half after the operation he fed 

 eagerly again and again, seeming to relish his food as much as 

 if not mutilated. At half past nine in the evening, or five and 

 a half hours after the loss of his abdomen, he was evidently 

 dyino; ; the mandibles were set together, he lay on his back, and 

 the tarsi were twitching convulsively, while a female Polistes 

 which was beheaded at four in the afternoon of the previous 

 day was as lively as ever. One would have supposed that the 

 male without abdomen would have outlived the decapitated 

 female. 



The female referred to was beheaded at four in the afternoon 

 of the day previous, and was living twenty-four hours after- 

 wards, being lively, standing on her legs and opening and shut- 



