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



ent symptom of pain. Concerning a little timber-boring beetle, 

 Anobium pertinax, De Geer (5, p. 229) claims that "yo^ may 

 maim them, pull them limb from limb, roast them alive over a 

 slow fire, but you will not gain your end; not a joint will they 

 move, nor show by the least symptom that they suffer pain. 

 A similar apathy is shown by some species of saw-flies (Serrifera), 

 which when alarmed conceal their antennae under their body, 

 place their legs close to it, and remain without motion even 

 when transfixed by a pin. Spiders also simulate death by fold- 

 ing up their legs, falling from their station, and remaining motion- 

 less; and when in this situation they may be pierced and torn 

 to pieces without their exhibiting the slightest symptom of pain." 



We repeated one of De Geer's experiments on Belostoma, 

 but in not a single instance could a specimen be roasted to death 

 without its first coming out of the death feint and making violent 

 efforts to escape. Severe mutilations were also performed with 

 Belostoma. If one of the limbs be snipped in two with a pair 

 of fine scissors, the bug may not respond at all, or the limbs 

 may twitch or quiver, or the insect may right itself and scramble 

 eagerly to get away. One or two repetitions of this experiment 

 with those specimens which did not come out of the death feint 

 immediately after the cut was made, was sufficient to bring them 

 out. We often noticed with these mutilated specimens when 

 they were put back into the death feint in order that we might 

 again repeat the brutal experiment, that the beak would grope 

 around, the styliform mouth-parts protrude and retract, and a 

 white liquid be discharged and collect at the base of the beak.' 



The behavior of Nepa, when mutilated or dismembered, is 

 entirely different from that of Belostoma. Several Nepas, which 

 were feigning death, were placed upon their backs, and with a 

 pair of fine scissors the tibia of each leg was cut in two with a 

 sharp, quick cut. Not even a quiver was noticed. Each femur 

 was then cut in two and yet the insect did not give any apparent 

 sign of feeling. The tip of the abdomen of each specimen was 

 now snipped off and still no movement was to be seen. Finally 



' Locy (17, pp. 355-6) has found what he calls the " cephalic glands " which 

 open externally by means of short ducts on each side of the head between the eyes 

 in the genera Lethocerus, Belostoma and Ranatra. " When these insects are 

 irritated, a secretion is freely thrown out around the base of the beak, which pro- 

 duces death very quickly when introduced on a needle point into the body of an 

 insect." 



