50 Trans. Acad. 8ci. of St. Louis ^ 



test this matter, I selected one hundred ant-lions and, by 

 proper manipulations, made it possible for each to have 

 an opportunity to make twenty successive letisimulations. 

 These experiments revealed marked individual varia- 

 tions. The longest feint occurred anywhere from the 

 first to the sixteenth feint; although it usually occurred 

 near the beginning of the series. This irregularity in the 

 location of the longest feint is in accord with the work of 

 the Severins (Jour. N. Y. Entom. Soc, 1911, Vol. XIX, 

 pp. 99-108) and of Gee and Lathrop (Ann. Ent. Soc. of 

 Amer., 1912, Vol. V, pp. 391-399) on the giant water bugs 

 and the plum cuculio. 



To see if the duration and location of the maximum 

 feint and the total time consumed in the series of leti- 

 simulations mentioned were factors of external stimuli, 

 experiments were devised to test the effects of tempera- 

 ture, strength of the inducing stimulus and hunger. 

 There did not seem to be any relation between these 

 stimuli and the results. These phenomena seem to de- 

 pend upon the individuality of the ant-lion; i. e., upon 

 internal physiological states which vary in different indi- 

 viduals and in the same individual at different times. 



It seems to me that even a layman cannot listen to a 

 recital of such peculiar behavior as that mentioned above 

 without asking, ''What does it indicate as to the psycho- 

 logical status of the individuals?" Weir (Dawn of Rea- 

 son, 1889, p. 202) considers the letisimulation of animals 

 "one of the greatest evidences of intellectual action on 

 their part." Hamilton (Canad. Entom., 1888, p. 179), 

 Webster (Canad. Entom., 1888, Vol. XX, p. 199) and a 

 few others feel that the creatures consciously fear death 

 and take this means of avoiding it. Dr. Lindsley, in 

 "Mind in Animals," thinks "this must require great com- 

 mand in those that practice it." However, the majority 



