12 HENRY H. P. SEVERIN AND HARRY C. SEVERIN 



A glance down any of the columns of figures shows that the 

 duration of successive death feints diminishes with repeated 

 trials. 



The above experiment was repeated with ten different Belos- 

 tomas taken from water at 15° C, and exposed to the tempera- 

 ture of the atmosphere at 22° C. The total ntimber of minutes 

 and the number of times each specimen could be induced to 

 feign in both of these experiments is shown in the following 

 table : 



TABLE III. 



While experiment I was being carried on, a similar series of 

 experiments were started at 8 a. m. with two Belostomas that 

 had attained their full growth by moulting during the night. 

 With these specimens, the duration of the death feint also dimin- 

 ished with successive trials. It was found, however, that the 

 total average time that these two bugs could be induced to feign 

 was only one hour, whereas in experiments I and II the total 

 average time was five and four and one-half hours respectively. 

 This difference may be attributed, in part at least, to the weak- 

 ness following the tedious task of moulting which these two 

 specimens had recently undergone, and also to the effect of 

 dryness upon the organisms. 



As soon as the ten Belostomas, which were used in experi- 

 ment I, refused to feign, they were thrown into an aquarium. 

 After remaining in the water for a few minutes, they could 

 again be induced to feign death, and were put through successive 

 feints until they refused to feign longer, when they were thrown 

 into the aquarium a second time. This was repeated until 



