DEATH FEIGNING REACTIONS IN TYCHIUS PICIROSTRIS 147 



at low temperatures some other factor than those concerned 

 in the production of the death feint does not come into play. 



As stated above it was found impossible at room temperature 

 to induce the feint in decapitated insects. Near the freezing 

 point, however, the feint was evoked without difficulty. Under 

 the microscope a slight twitching of the legs could be observed 

 in the decapitated insect during the feint. On being removed 

 to the table the insect resumed the twitching movements. 



The anterior portion of weevils severed across the thorax 

 also feigned death readily, and the duration of the feint was 

 longer than at room temperature. 



It will thus be seen that cold lowers the threshhold of stimu- 

 lation and reduces the shock effects of mutilation. 



These results agree closely with those obtained by Gee and 

 Lathrop on Conotrachelus nenuphar Herbst and by Holmes on 

 Ranatra. 



Effect of Chloroform and Ether on the Death Feint. Insects 

 feigning death were introduced into the vapor of chloroform 

 and of ether. Chloroform seemed to have little effect on the 

 duration of the first feint, but of fourteen individuals tested 

 five could not be induced to feign a second time. The others 

 with one exception could only be induced to feign death twice 

 and this one exception was anaesthetised during the fourth feint. 



TABLE III 



The Effect of Chloroform on the Duration (in Seconds) of Feint, and 

 on the Number of Successive Feints of Fourteen Individuals 



14 



20,3 



* Partial feint. 



In three cases, stimulated by pinching with forceps while 

 lying on their backs, it was found that the insects would draw 

 up their legs to the feigning attitude, but relaxed them and 

 resumed their struggles on being released from the forceps. 



In the case of ether the results were different. A longer 

 succession of feints could be obtained, but the ether had the 



