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



loss of blood which had oozed out from the wound after de- 

 capitation had taken place. 



22. Reactions of Belostoma and Nepa with the body severed 

 between the prothorax and mesothorax: In cutting the body of 

 Belostoma or Nepa between the prothorax and mesothorax, 

 neither the fused infra-oesophageal and first thoracic ganglia, 

 nor the large ganglion, which innervates the posterior pairs of 

 legs and the abdomen, are injured. In Belostoma, the wound 

 of the part anterior to the cut is exceedingly large, whereas in 

 the posterior portion it is rather small. 



When the body of feigning Belostomas was severed between 

 the first two thoracic segments, both parts usually remained in 

 the death-feigning attitude, whereas decapitation, as a general 

 rule, brought the water bugs out of the death feint. If the part 

 posterior to the cut (mesothorax, metathorax and abdomen 

 intact) is thrown into water, it may make a few feeble strokes 

 in an attempt at swimming, but not in a single instance did such 

 a part swim about actively as was often the case with decap- 

 itated specimens. 



In one set of experiments ten Belostomas, while they were 

 feigning death, were cut in two between the prothorax and meso- 

 thorax. After the cut was made, both parts of the body of two 

 specimens came out of the death feint immediately; the two 

 parts of the remaining specimens, however, maintained the death- 

 feigning posture, some not even giving as much as a quiver 

 when the body was severed. The following table shows the time 

 in minutes that each part remained in the death-feigning attitude : 



TABLE V. 



Duration of the Death-Feigning Posture in Eight Belostomas After the 

 Body was Severed Between the Prothorax and Mesothorax; Tem- 

 perature OF Atmosphere 21° C; of Water in Which 

 Belostomas Were Kept 19.5° C. 



Head and Prothorax Mesothorax, Metathorax 



Intact. and Abdomen Intact. 



A 

 B 

 C 

 D 

 E 

 F 

 G 

 H 



Average 



