f 



212 Studies in Animal Behavior 



Severins showed the same phenomenon in Nepa and 

 Belostoma. Fabre in his studies on Scarites found 

 an increase in the duration of the first five feints, but 

 his observations were not sufficiently numerous to 

 eliminate the rather large amount of variability due 

 to unknown causes. 



As the feints grow shorter the attitudes of the 

 organism become less characteristic. Amphipods 

 and pill-bugs do not roll up so completely or keep 

 the appendages drawn so closely to the body. Spi- 

 ders and beetles do not assume so compact a form, 

 and in general it may be said that the muscular sys- 

 tem gives evidence of diminished contraction. As 

 the death feint Is usually accompanied by a tetanic 

 contraction of the muscles one would expect to find 

 a diminution in the duration and perfection of the 

 response as a simple consequence of fatigue. In a 

 similar manner the diminution of the duration of 

 the feint that occurs under higher temperature may 

 be due to the fact that the muscles become exhausted 

 more quickly when the metabolism is increased by 

 the higher temperature of the body. 



The experiments undertaken to ascertain what 

 part of the nervous system Is most concerned In the 

 death feint have yielded somewhat varied results. 

 Robertson found that in the active species of spiders 

 Epeira and Amaurobius the sham death reaction per- 

 sisted after the removal of the brain, and was mani- 

 fested in a weakened form when the subesophageal 

 ganglion and even the first thoracic were removed 



