STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 23 



the insects like a pendulum. A shade was used to reflect as 

 much light down upon the specimens as possible. The heat 

 rays were intercepted by placing a flat dish containing an inch 

 and a half of pure water between the electric lamp and the 

 bugs. This work was carried on in a darkened room, so that 

 the insects experimented with were exposed to light only from 

 this lamp. 



Holmes (12, p. 208) finds that Ranatra comes out of the 

 death feint more quickly under a bright light than under a much 

 dimmer light, a result which we also obtained with Belostoma 

 and Nepa. In one set of experiments, six of twelve Belostomas 

 were put into the death feint and then exposed to the light of 

 a stationary sixteen candle-power electric lamp, while at the 

 same time, the remaining six were caused to feign in a much 

 dimmer light in another part of the room. None of the insects 

 had been exposed to the light of the incandescent lamp pre- 

 vious to the time that they were put into their first feint. The 

 results were as follows: averages of three successive death 

 feints in six Belostomas kept under a stationary sixteen candle- 

 power incandescent electric lamp 4.5, 10, 13.5, 21, 21 and 26 

 minutes, the total average being 16 minutes; averages of three 

 successive death feints in six Belostomas kept under a much 

 dimmer light 27.5, 28.1, 28.5, 28.5, 29 and 30 minutes, the 

 total average being 28.6 minutes. The difference between these 

 two total averages is 12.6 minutes, from which one would not 

 hesitate to conclude that the awakening occurs more quickly 

 under a bright light. 



Nepa also feigns death longer, as a rule, in a dim light than 

 in bright light, provided the insects have been previously exposed 

 for some time to that intensity of light in which they are after- 

 wards made to feign. In the two following experiments, two 

 lots of specimens w^ere exposed for three hours to the light of a 

 sixteen candle-power incandescent electric lamp about twelve 

 inches away, while two other lots were being kept in a much 

 dimmer light for the same period of time. They were all then 

 made to feign in the usual manner with as nearly the same 

 amount of handling as possible and transferred to practically 

 the same intensity of light to which they had been exposed. 

 In these experiments there was no shock effect due to change in 

 temperature, for the water in which the insects were kept was 



