STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 35 



between the prothorax and mesothorax, were exposed to a 

 swaying sixteen-candle power electric lamp. The part containing 

 the head usually came out of the death feint more quickly than 

 the posterior portion and show^ed marked responses to the light, 

 while the latter would not react to it at all. As in the intact indi- 

 viduals, but few of the anterior parts, when placed dorsal side 

 upward upon a table, gave the lateral and vertical head move- 

 ments in response to changes in the position of the light previous 

 to coming out of the death feint. After coming out of the death 

 feint, the anterior portion endeavored to follow the light, the 

 raptorial claw-like tibiae and tarsi catching hold of the table 

 and dragging the head and prothorax along. 



Five Nepas, while in a death feint, were cut across the 

 metathorax behind the last ganglion and without exception 

 every anterior portion continued to feign death. A light was 

 then passed back and forth over these anterior parts and soon 

 they gave the head reflexes apparently as well as normal Nepas. 

 After coming out of the feint, these anterior parts were decid- 

 edly negatively photo tactic, walking" away from the light as well 

 as possible, often falling over forward upon their back, but soon 

 righting themselves again and continuing on their path away 

 from the light. 



VIII. THE ORIGIN AND DEVELOPMENT OF THE DEATH FEINT. 



Various theories of the origin and development of the death 

 feint have been advanced, but it is by no means evident that 

 the development has been the same in all cases. Preyer (24) 

 ascribes the shamming dead of insects to the exclusive influence 

 of " kataplexy," or mesmeric sleep. Romanes (24, p. 309) 

 believes with Preyer that "the shamming dead of insects is a 

 phenomenon in which the principles of hypnotism are probably 

 concerned. But if so, I regard these principles only as furnishing 

 the materials out of which natural selection has constructed 

 this particular instinct. Therefore, whether or not these prin- 

 ciples are really concerned in the phenomenon, is only a side 

 question; the important consideration for us is, that the instinct, 

 whether or not developed from materials supplied by kataplexy, 

 must certainly have been developed by natural selection." 



Holmes (8, p. 195), who studied death feigning in terrestrial 

 Amphipoda with the end of ascertaining, if possible, how their 



