204 'Journal of Comparative Neurology and Psychology. 



beetle feigned for seventeen, twenty, twenty-five, thirty-three and 

 fifty minutes in successive trials; and other experiments the details 

 of which are not given w^ere found to yield similar results, although 

 there was very great variability in the lengths of the responses. 

 The insect, however, could not be induced to feign indefinitely; 

 sooner or later all efforts failed to make it fall back into the death 

 feint, as if it found the ruse useless and decided not to persist in it. 

 My own experiments upon quite a number of unrelated forms 

 have shown that in nearly all cases the duration of the death feint 

 diminishes instead of increases with successive trials. Details of 

 these experiments will appear in a future paper. Ranatra forms no 

 exception to this rule, although there is usually a very great amount 

 of variation in the duration of the first feints. In the experiments 

 whose results are recorded in the following table ten Ranatras 

 were picked up, stroked to about the same degree, and laid down 

 on the table. As soon as a specimen awoke it was immediately 

 picked up and caused to feign again, and its time of awakening 

 recorded. This was continued as long as any of the Ranatras 

 would feign. All of the specimens were exposed to the same 

 amount of light, and the temperature of the room was kept nearly 

 constant. The experiment was begun at 9 a. m. and continued 

 without any interruption until 5 p. m., when the last specimen 

 refused to feign longer. 



Table Showing the Duration in Minutes of Successive Death Feints in Ten Specimens of 



Ranatra. 



Continued on next page. 



