STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 13 



finally the insects absolutely refused to feign. The total average 

 time which the ten Belostomas feigned throughout all the series 

 of successive death feints was eight hours; the total average 

 time of the first series of successive death feints was five hours, 

 thus making an increase of three hours that the specimens could 

 be induced to feign by placing them in water for a short time 

 whenever they refused to assume the inert state. 



Towards the end of this series of experiments, the tetanic 

 condition of the leg muscles became weaker and of shorter 

 duration. When one of these specimens was taken from the 

 aquarium and put into the usual death-feigning posture, it 

 would maintain this position only for a short time; the legs 

 would spraw^l apart and often the insect would make no attempt 

 to right itself. Consequently it often became exceedingly diffi- 

 cult to say with certainty just when the death feint ended. 

 When thrown into the aquarium, the bug would swim about 

 rather listlessly. One would naturally be inclined to believe 

 that these w^eaker responses were due to fatigue, but that this 

 is not entirely the case will be shown later. After these series 

 of experiments were discontinued, the ten Belostomas were kept 

 over night in the aquarium and the next morning we were 

 surprised to find that most of the individuals had died. 



The previous experiments on how long successive death feints 

 can be continued suggested a number of problems : (i) the cause 

 of the weaker reaction toward the end of this series of experi- 

 ments, if it is not entirely due to fatigue; (2) the reason for the 

 marked diminution in time of the death feints with successive 

 trials; (3) the cause of the cessation of the feint in each series 

 of successive death feints, if it is not wholly due to fatigue; 

 and (4) the probable explanation of the death of most of the 

 ten Belostomas. 



A similar series of experiments were carried on with ten Nepas, 

 Every specimen was made to feign by taking it out of the water 

 with a pair of forceps, dropping it upon a moist blotter from a 

 small height and turning it over and over laterally three or 

 four times. The insects were now laid upon a table upon their 

 ventral surface, but it was found that it became impossible at 

 times to determine positively when the death feint ended . Al- 

 though the bugs would assume a walking attitude after they 

 had given the first signs of coming out of the death feint, yet 



