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POPULAR SCIENCE MONTHLY 



instinct. Among Crustaceans the instinct in its fully developed form 

 ib quite uncommon. Some years ago I described the death-feigning of 

 certain species of terrestrial amphipod crustaceans which are frequently 

 found on sandy beaches near the seashore. On account of their pe- 

 culiar hopping movements these crustaceans are commonly known as 

 sand-hoppers or sand-fleas, although they have of course no relation to 

 the ordinay fleas of human experience. One of the largest species of 

 sand-hopper, Talorchestia, is common along our Atlantic coast, where 

 it lives during the day in burrows made in the sand, coming out only 

 at night to feed upon the seaweed and other material washed ashore 

 by the waves. When the Talorchestias are dug out of their burrows, 



Fig. 3. A Sand-flea, Talorchestia, in the Death Feint. 



they usually lie curled up with their long antennae bent under the body 

 and their legs drawn up so as to assume a compact form. They will 

 lie in this way for several minutes, when they may be seen slowly to 

 relax; the legs then move about, and soon the creature hops away by 

 a sudden extension of its abdomen. When caught in the hand they 

 will feign death again, and repeat the performance many times in 

 succession. Other species of sand-hoppers exhibit the same instinct, 

 though less perfectly, and there are traces of it in many of the reac- 

 tions of their aquatic relatives. 



The various species of wood lice exhibit the instinct of feigning 

 death in various degrees. Some species are able to roll up into an 

 almost perfect ball and will remain in that state for a considerable 

 time. Other species curl up, but make only a very imperfect approxi- 

 mation to a sphere, and they may not maintain this attitude but for a 

 short period. Some myriapods when disturbed curl up in much the 



