STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 33 



Immediately after coming out of the death feint, the parts 

 posterior to the cut were thrown into the water in which the 

 specimens had been swimming just before the body was severed. 

 They were then taken from the water and handled in the usual 

 manner to bring about the death feint. Two of the ten water- 

 bugs could be induced to assume the characteristic death-feigning 

 posture, but only one showed any signs of a muscular contrac- 

 tion of the legs when stroked with a camel's hair brush. Twenty 

 hours after the operation, the severed posterior portions of the 

 body of the ten Belostomas were again treated as before, with 

 somewhat similar results. 



It is evident from the previous experiment, that the severed 

 posterior portion of the body remained in the death-feigning 

 posture often for a considerable length of time after the cut was 

 made; but that this was often due to a shock effect in some 

 individuals may be seen from the following observations. After 

 the body of a particular specimen was severed between the first 

 and second thoracic segments, the part posterior to the cut 

 righted itself and assumed a very awkward position. The 

 posterior pairs of legs were extended stiffly forward, there being 

 no bending in the femoro-tibial joints. The anterior part of the 

 body was raised high into the air, while the posterior portion 

 touched the substratum. Unquestionably it was the shock 

 effect which produced the rigidity of the leg muscles in this 

 mutilated individual. With some specimens when the cut was 

 made, the legs would not merely quiver, but would move up 

 and down repeatedly and then become rigid again. Here again 

 there is a renewed tetantic condition brought on, in all proba- 

 bility, through a shock effect. 



Holmes (12, p. 213), in his work with Ranatra, cut a feigning 

 specimen in two across the prothorax and found that "the 

 posterior portion of this specimen continued to retain its rigidity 

 for some time after it was cut off, - - - - . If it is picked up 

 and stroked, it may be thrown back into the death feint again, 

 but it remains in this state for only a comparatively short time." 



Fifteen Nepas were cut through the posterior region of the 

 prothorax and in nearly all cases the anterior portion continued 

 to feign death; the posterior part, however, either lost the 

 rigidity of the legs immediately or remained perfectly quiet 

 for an indefinite period, in which case, it was impossible to say 



