STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 9 



the insects were cut through the middle of the prothorax and 

 both parts remained quiet, the posterior part, however, losing 

 the rigidity of the muscles almost immediately. A number of 

 individuals, which were feigning death, were placed upon a hot 

 stove, but all without a single exception came out of the feint 

 immediately. Placing them upon the surface film of water even 

 as low as 40° C. gave the same results. A number of specimens 

 were laid upon a stove at a temperature of 21° C, and then the 

 temperature was gradually increased, but in not a single in- 

 stance could an individual be roasted to death without its first 

 coming out of the death feint and making violent efforts to 

 escape. 



III. DURATION OF SUCCESSIVE DEATH FEINTS. 



7. Duration of the first five successive death feints: Fabre 

 (6, pp. 15 and 16) put a beetle, Scarites gigas. Fab. into five 

 successive death feints and found that, " Les cinq epreuves 

 cons^cutives, de la premiere a la derniere, ont dure respective- 

 ment 17 minutes, puis 20, 25, t^t, et 50 minutes. lis nous disent 

 qu'en general le Scarite prolonge da vantage sa pose inerte k 

 mesure que I'epreuve se repete." We performed a similar ex- 

 periment with a half dozen Belostomas which were taken from 

 water at 21° C, and caused to feign five times at the temperature 

 of the atmosphere at 21° to 23° C. Each specimen was placed 

 with its back upon a solid substratum and as soon as it came 

 out of the feint, it w^as immediately put back into its inert state 

 again, care being taken to give each individual about the same 

 amount of handling and to keep conditions as nearly uniform 

 as possible. The temperature of the room varied within two 

 degrees throughout the experiment. The following figures show 

 the duration of the first five successive feints in minutes : 



Average 11.5 13.4 15.5 18.3 18.5 21.4 



16.4 Total average 



