2io Studies in Animal Behavior 



found to diminish the duration of the feint in both 

 of these species, owing possibly to the shock effect 

 of the sudden change. 



The influence of light on the duration of the feint 

 has been studied by the Severins in the forms just 

 mentioned and by myself in the water bug Ranatra. 

 The results agree in showing that the duration of 

 the feint is greater in dim than in strong light, and 

 that the feint is further shortened if a light is kept 

 moving over the insect. The latter result, like the 

 former, is probably due to the greater stimulation 

 to which the feigning insect is subjected. As all 

 these water bugs are positively phototactic, light 

 tends to elicit an active response which antagonizes 

 the instinct of feigning death. In a Ranatra which 

 is induced to come out of the death feint by moving 

 a light above it, the first signs of life manifested 

 are orienting movements of the head which take 

 place in perfect unison with the movements of the 

 light. These are followed by swaying movements 

 of the body, until finally the insect attempts to follow 

 the light by walking or, if highly excited, by flying. 



It is a curious fact that while the water bugs, 

 Nepa, Belostoma and Ranatra, feign death very 

 readily when out of the water, they will do so much 

 less readily when submersed in their natural ele- 

 ment. In Ranatra repeated manipulations under 

 the water usually fail to elicit anything but a mo- 

 mentary and undecided response. Nepa under the 

 same circumstances feigns for a somewhat longer 



