STUDY ON THE DEATH-FEIGNING OF BELOSTOMA 5 



evident that the muscles of the limbs must be in a state of ex- 

 treme contraction; but if, on the other hand, this is done when 

 the bug is not feigning death, the tibia offers almost no re- 

 sistance. 



Nepa, while feigning death, may be taken by any tibia or 

 femur and held in a position so that the weight of the entire 

 body is borne by the extensor muscles of a single segment of 

 but one leg, and yet this position will be maintained until the 

 weight of the body causes the muscles to relax, when the body 

 descends slowly. Again, when any attempt is made to bend a 

 leg while the insect is simulating death, it is found that the 

 muscles are in an extreme state of contraction. Nepa, while 

 in this state of tetanus, may be placed in a great variety of un- 

 natural positions, and still these will be maintained for some 

 time. When a Nepa, that is not feigning death, is experimented 

 upon as above, it will be found that the muscles are not set and 

 no unnatural positions will be maintained for any length of 

 time. 



If one compares the attitude of a Belostoma which has just 

 been caused to feign by the usual method (fig. 2) with an indi- 

 vidual which was feigning on its back for a considerable time, 

 it will be noticed that in the latter, the posterior pairs of legs 

 have usually spread apart considerably while the front 

 pair droop more or less towards the head. This movement of 

 the limbs is so slow that it is imperceptible and must be ac- 

 counted for by the gradual relaxation of the muscles. 



Preyer ' in his work on the guinea pig observed that, "Wahrend 

 des Zustandes der Bewegungslosigkeit stellt sich bei einzelnen 

 Thieren nach einigen Minuten oft ein Zittern aller Extremitaten 

 ein, das ziemlich stark werden kann und haufig mit ein Auf- 

 stehversuch endet. Ueberhaupt werden nicht selten von den 

 Thieren Aufstehversuche gemacht, die aber oft, ohne zum Ziele 

 zu fiihren, im Keime stecken bleiben. Die Thiere sind dann 

 gleich darauf wieder voUkommen ruhig." 



We also have observed a twitching or a quivering of the limbs 

 in some Belostomas while they were lying on their back in a 

 death feint. The beak may grope around and the styliform 

 mandibles and maxillae may be protruded and retracted in a 

 threatening manner ; or the feigning individual may move the 



^ Quoted from Verworn's (27, p. 6) paper. 



