504 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



the same. Little by little he cut off the antennae and began to cut 

 off pieces of the forelegs ; the insect is bleeding, but remains unmoved. 

 He even cut off bits of the abdomen and still it remained unmoved. 

 But let it be pinched on the cut end of the abdomen, i. e., given pro- 

 tracted excitement of the nervous system, it wakes from the trance 

 and runs away. 



No doubt, therefore, this is catalepsy. An experiment similar to 

 hypnotism, may be performed with the insect by placing the ends 

 of the extended legs and antennae on one book, end of abdomen on 

 another. Strips of paper may now be placed on the middle and 

 the body thus weighted down, but the insect does not stir. 



To ascertain the parts of the body with which catalepsy in Carau- 

 sius is associated, what produces it and what is its biological sig- 

 nificance and genesis, the author took a resting specimen and 

 snipped it in two in front of the mesothoracic legs. The body re- 

 mained standing on the four legs as if nothing had happened and the 

 front part fell, also without changing pose. Several minutes later, 

 however, the legs weakened apparently, and no longer supported 

 the weight of the body, which sank to the surface of the table, but 

 the legs retained their former position. But when the leg muscles 

 were examined it was found their waxen flexibility had vanished. 

 The body became very sensitive, reflex action is manifest. When a 

 leg is touched it contracts and often the other legs also. Other 

 tests showed that no trace of catalepsy was left in this part of the 

 body. Some muscles, on the other hand, showed signs of a tetanus 

 state, the seized legs breaking at the joints. He notes, by the way, 

 the great vitality of this half of the insect; ligatured and protected 

 from excessive desiccation it lived in one instance 12 days. 



The head end has less vitality, lives only two or three days, but 

 otherwise behaves as if it were attached to the body, the brittleness 

 of the legs in the coxal joint being the only difference. Catalepsy is 

 still there, if not so pronounced as normally. For hours the legs 

 and antennae remain extended cephalad, and can be placed in any de- 

 sired position. By excitation it can be brought into activity. 



The difference in behavior between the two halves of the body 

 is explained by the fact that catalepsy depends on the head ganglia 

 (the prothoracic, he found, does not count) and is induced by some 

 special internal conditions surrounding muscles and nerves (like 

 special composition of blood, excess of carbonic acid in it, etc.) and 

 in all probability is a special form of nerve excitation. This specific 

 excitation is produced by unknown processes in the central organ 

 of the nervous system, and, permeating the entire nervous system, 

 produces depression of reflex action, of sensation and a special state 

 of muscle shortening bordering on contraction. The results of these 



