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



normally follows when the inhibiting influence of the supra - 

 oesophageal ganglion is no longer exerted;" and the very much 

 weaker response may possibly be due to the loss of blood which 

 had oozed out from the wound after decapitation had taken 

 place. 



With Nepa, decapitation always resulted in the immediate loss 

 of the muscular rigidity. While the legs of some of these de- 

 capitated specimens would become rigid when the insects were 

 stimulated with a camel's hair brush, still this condition, like 

 that in Belostoma, was only of short duration. 



11. When the body of Belostoma is cut in two between the 

 prothorax and mesothorax, both parts usually continued to 

 feign death. The part posterior to the cut often remained in 

 the death-feigning attitude for a considerable length of time 

 after the operation. After the severed posterior portions come 

 out of the inert condition, many cannot be induced to assume 

 the usual death-feigning attitude ; others will assume the death- 

 feigning position, and when the abdomen is stroked with a 

 camel's hair brush, the legs show evidence of a weak tetanic con- 

 dition of but short duration which may in a very small per cent, 

 of cases be maintained longer than one-half minute. It seems 

 probable, that in some individuals at least, the shock effect may 

 perhaps cause a renewed tetanic condition of the leg muscles, 

 which condition may last for a considerable length of time after 

 the cut was made. With the exception of the behavior shown 

 immediately after severing the body, the reactions of the severed 

 posterior portion of the body of Belostoma is somewhat similar 

 to that of the decapitated individual. 



If the body of Nepa is severed between the first two thoracic 

 segments, the part anterior to the cut will react very similar to 

 the intact specimen, while the posterior portion behaves like 

 decapitated individuals. 



12. When Nepa is cut across the metathorax behind the last 

 ganglion, the severed posterior part does not respond to any 

 sort of a stimulus ; the anterior portion, on the other hand, 

 again reacts similar to the intact bugs. 



We are indebted to Prof. S. J. Holmes for many valuable 

 suggestions in this work and for the constant use of literature 

 borrowed from his library. 



