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



toma will crawl, whenever possible, beneath aquatic plants or 

 other objects and will then often assume that death-feigning 

 attitude in which the legs are folded against the ventral surface 

 of the body (fig. i). Specimens, which had cuddled within 

 thick masses of Elodea or Ceratophyllum, often required a con- 

 siderable amount of shaking to bring them out of their inert 

 state. Nepa can be caused to feign while in water by a mere 

 contact stimulus. 



One would be inclined to believe that successive death feints 

 in the water would interfere with the respiration of those insects 

 which come to the surface to breathe, and one would naturally 

 expect, as our results show in the case of Belostoma and Nepa, 

 that there be. a marked decrease in the duration of the death 

 feint when these insects are caused to feign in the water. As 

 already mentioned, Nepas were made to feign again and again 

 before they were permitted to reach the surface film with their 

 breathing tube, but all efforts to put these insects into the 

 death feint, without allowing them first to reach the surface 

 of the water with the breathing tube failed. If these specimens 

 were permitted to take in air, however, they could very readily 

 be put into the death feint again. 



IX. THE PSYCHIC ASPECT OF THE DEATH FEINT. 



There is a lack of evidence obtained through experimental 

 methods to show that the higher vertebrated animals feign 

 death as a result of conscious reflection in order to deceive 

 their enemies. Verworn has observed that many of the higher 

 animals are keenly aware of visual, auditory and olfactory 

 stimulations w^hile they are in the so-called hypnotic state. In 

 the case of the hen, he (27, p. 44) writes, " Dagegen habe ich 

 mich bei Hiihnern ganz deutlich da von iiberzeugen konnen, dass 

 sie durch schwache Wendungen des Halses und Kopfes meine 

 Bewegungen verfolgten, besonders, wenn ich hinter sie trat, so 

 dass sie, um deutlicher zu sehen, den Kopf immer nach der 

 Seite meiner Bewegung etwas umdrehen mussten. - - - - Es 

 ist also zweifellos, das die Thiere alle Vorgange, die in ihren 

 Gesichtskreis fallen, mit grosser Aufmerksamkeit verfolgen und 

 dass der Gesichtssinn durchaus in wachen Zustande ist." Accord- 

 ing to Holmes (14, pp. 184-5) death-feigning, " is doubtless 

 associated in birds and especially mammals with a tolerably 



