DEATH FEIGNING REACTIONS IN TYCHIUS PICIROSTRIS 139 



will assume the death feigning attitude for a few seconds, and, 

 on recovery, turn over and either scramble away immediately 

 or remain quiescent for a brief period before moving away. 

 A few of those which fall on their backs will not feign death 

 but will turn over and move away at once. 



Of those which fall to the ground right side up some will 

 remain quiet for a short time with their legs in the normal 

 resting position, others will run away immediately on reaching 

 the ground but very few will assume the typical death feigning 

 attitude. 



In the laboratory the feint was obtained in one of three ways : 

 by dropping the insect on the desk, by pinching it lightly with 

 a forceps or by merely turning it on its back. The last method 

 was usually successful in evoking the death feigning response 

 and was generally employed. After remaining in the feint for a 

 variable period the insect relaxes its legs and struggles to turn 

 over. On turning over, or on being turned over the insect 

 scrambles away, but while it is running it may be induced to 

 feign a second time by again turning it on its back, and within 

 certain indefinite limits to be indicated below this process may 

 be repeatedly successful. 



While struggling on its back the insect may be induced to 

 feign death by tapping it on the sternum. If, however, it is 

 in the normal position, with its back turned up it will not feign 

 death on being tapped on the back; on the contrary a quiescent 

 insect thus treated will become active. 



The intensity of the shock seems to have no effect on the 

 production or duration of the death feint, as an insect which 

 has been merely turned over, or dropped from a height of six 

 inches remains in the death feint as long as one dropped from 

 a height of eight feet or more. It was also found that if the 

 feint could not be elicited by overturning the insect or by drop- 

 ping it from a height of six inches or thereabouts, it was im- 

 possible to produce it by dropping from greater heights up to 

 eight feet, or even by lifting with forceps and forcibly dashing 

 to the table. 



It was found impossible to obtain the death feigning reaction 

 with some individuals. As the insects experimented on had 

 matured some time previous to the period of these investiga- 

 tions and had not been under constant observation from the 



