THE PSYCHOLOGY OF "PLAYING 'POSSUM" 



By C. H. TURNER 



Playing 'possum, feigning death, letisimulation — to 

 use in succession the language of the southerner, the 

 Bostonian and the behaviorist — are terms for a form of 

 behavior which is as widespread as it is remarkable. 

 Any one who has hunted opossums in the south has 

 observed an interesting exhibition of it. When an opos- 

 sum is attacked, usually it falls to the ground, draws 

 back its lips and looks as though dead. You may toss it 

 about, kick it, pinch it, do what you may, but not a sign 

 of life will you get. Individual specimens have been 

 known to remain as though dead for hours. This pecu- 

 liar method of protecting itself from danger is found 

 throughout the animal kingdom. Not all animals, nor yet 

 all species, practice it, but from the protozoa upward, 

 almost all groups of active invertebrates contain certain 

 species that practice it, and among the vertebrates some 

 members of all groups letisimulate. So widespread is 

 this phenomenon that AVeir, in his Dawn of Reason, 

 thought it wise to coin a scientific name for it. He called 

 it letisimulation (from letum, death, and simulare, to 

 feign). 



All students of one-celled animals have noticed Vorti- 

 cella fold in its cilia, coil its flexible stalk and retreat 

 against a support when approached by a larger inverte- 

 brate. Weir noticed that the approach of certain water 

 fleas caused a species of rhizopods to drop to the bottom 

 and to remain quiet until the larger creatures had dis- 

 appeared. 



There is an annelid worm about one-eighth of an inch 



