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



The following question naturally suggested itself: Does the 

 transition from water at a low temperature to a higher temper- 

 ature of the atmosphere have any effect upon the duration of 

 the death feint? Thirty-five Belostomas were taken from w^ater 

 at 3° C. and exposed to the temperature of the atmosphere at 

 21° to 2 2° C. Many specimens absolutely refused to feign when 

 taken out of this cold w^ater, w^hile others would remain in the 

 inert state only a few minutes at the most. Those individuals 

 which did feign, always assumed that death -feigning pos- 

 ture in which the legs are folded against the ventral surface of 

 the body (fig. i) ; but later, as the insects overcame their numb- 

 ness, they could be induced to assume the characteristic death- 

 feigning attitude (fig. 2) and then they feigned for a consider- 

 able time. 



VI. THE EFFECT OF LIGHT ON THE DURATION OF THE DEATH FEINT. 



15. The effect of sunlight on the death feint: Fabre (6, pp. 21- 

 23), experimenting upon the effect of sunlight on the death feint 

 in two species of beetles writes, "Aussitot, sous les rayons directs 

 du soleil, le Scarite se retourne et deguerpit," and " En quelques 

 secondes de ce bein chaud et lumineux, I'insecte," (a Buprestid) 

 "entr' ouvre les elytres, dont il fait levier, et se retourne prompt 

 a prendre I'essor si ma main ne le happe k I'instant." 



With Belostomas the duration of the death feint is also de- 

 creased when the feigning insects are exposed to sunlight. Five 

 specimens were taken from water at 20° C. and caused to feign 

 in sunlight at a temperature of 36° to 37° C. The following 

 figures show the time, in minutes, of the first death feint in each 

 individual: .5, 3.5, 3.5, 5.5, and 5.5, the average time being 

 3.7 minutes. 



In working with direct sunlight, however, one cannot say 

 whether the duration of the death feint w^as diminished through 

 the direct effect of light upon the organism, or whether this 

 effect was due to the heat rays, or a combination of the two. 

 To overcome these difficulties an artificial light was used. 



16. The effect of an artificial light upon the duration of the 

 death feint: In the following experiment, a sixteen candle power 

 incandescent electric lamp was used, the lamp being attached 

 to a flexible cord of wire, which was fastened at one end to the 

 ceiling, so that the lamp could be swayed back and forth over 



