The Psychology of "Playing 'Possum** 49 



Several investigators have thought it important to 

 determine if the poses assmned by letisimulating indi- 

 viduals are death attitudes. Darwin was convinced 

 death-feigning attitudes are not identical with those 

 caused by death. Based on consideration of seventeen 

 species of invertebrates, Holmes (Pop. Sci. Monthly, 

 1908, Vol. LXXai, pp. 179-185) concludes that the poses 

 assumed were usually quite different from death atti- 

 tudes, although there were some species in which they 

 were always identical. I find that the ant-lion has not one, 

 but several, death attitudes ; likewise it possesses a num- 

 ber of death-feigning postures, some of which resemble 

 death poses and some of which do not. The insect be- 

 comes rigidly immobile in whatever attitude it may be 

 when it receives the shock. Absolute immobility is the 

 character that is connnon to all cases. AVhen the feint 

 follows a long period of fasting, this inactivity often sim- 

 ulates death. The rigidity, however, is not so great as 

 that described for certain insects. In some species of in- 

 sects the rigidity of parts during a death feint is so great 

 that the insect umy be picked up by the tarsus and held 

 out at right angles without the leg bending in the least. 

 That is not the case with the ant-lion. When an attempt 

 is made to lift it by a tarsus, the leg bends and the insect 

 awakes from its feint. 



With a pair of sharp scissors one may cut off the legs 

 and the tips of the mandibles of a letisimulating ant-lion 

 without arousing the slightest response. Attempt to cut 

 the legs with a pair of dull scissors and the insect awakes 

 at once. 



The duration of the death feint varies. Fabre, in his 

 study of a certain beetle (Souvenirs Entomologiques, 7th 

 series, pp. 11-27), found that the duration of the feints 

 gradually increased from the first to the fifth feint. To 



