DEATH FEIGNING REACTIONS IN TYCHIUS PICIROSTRIS 145 



tions of some or all of the legs were snipped off. In most cases 

 the insect remained in the feint, either making no response or 

 slightly twitching the legs. Sometimes, however, the insect 

 -became active on being dismembered. In some cases in which 

 the insect was in a partial feint the shock of removing the tarsi 

 induced a perfect feint. 



Removing the antennae of the feigning insect almost invari- 

 ably met with no response, the weevil remaining perfectly 

 quiescent. Individuals with the antennae and legs mutilated 

 could always be induced to feign again. 



Snipping off the beak always resulted in renewed activity 

 on the part of the subject except in one case, when the four 

 tarsi, both antennae and the rostrum were successively removed 

 without any manifestation of activity. It was found impossible 

 to induce the feint until some time after the mutilation, when 

 the shock effects of the operation had passed away. 



Cutting away the tip of the abdomen always caused the 

 insect to cease feigning. Insects thus mutilated, however, 

 could usually be induced to feign again, though often with 

 more difficulty than in the case of the normal individuals. 



Insects divided between the thorax and abdomen or between 

 the pro- and meso-, or meso- and meta-thorax always responded 

 by coming out of the death feint. The hinder portion could 

 not again be induced to feign death. In fact it did not live 

 very long after being cut off. The anterior portion, however, 

 gave the death feigning response but the threshhold of stimu- 

 lation was raised by the mutilation for it was necessary to drop 

 it to the table several times, or to tap it several times on the 

 sternum before the death feint could be elicited. In this con- 

 nection it may be advisable to state that only individuals which 

 reacted readily previous to mutilation were used in these tests. 



Decapitation invariably results in a feverish activity of the 

 limbs. The legs are worked to and fro, and the tarsi rubbed 

 against each other. At room temperature it was found im- 

 possible to obtain the feigning reaction with decapitated indi- 

 viduals. This is probably due to the shock effects of the very 

 violent disturbance in the central nervous system caused by the 

 mutilation, and not to any direct control of the supra-oesoph- 

 ageal ganglion over the death feigning reaction. 



