Atttotomy in Pliaamidee. 477 



possible, and the loss of blood had been in.si;^iilficant. The 

 ants succeeded once more in separatin;^ a third limb under 

 my very eyes, and there the i)rocess st >pped. I repeated the 

 experiment, and always with success; but in one solitary 

 case, in which the victim was a female Monatidfoptera, I was 

 able to remark the rupture of the whole of the limbs. The 

 anterior legs, where the base of the feumr is greatly attenu- 

 ated, are usually those in which the ants most easily succeed 

 in producing autotomy. 



The ants do not work by pulling, but, in truth, by bites 

 inflicted uj)on the interarticular tnembranc, between the coxa 

 and the trochanter, or between the femur and the tibia. The 

 action of a single ant is sometimes sufficient. In certain 

 cases autotomy takes place immediately, in others a certain 

 time elapses between the infliction of the bite and the moment 

 when amputation ensues. Thus, after having observed the 

 presence of ants upon the limbs of a Phasmid, it has happened 

 that I have picked up the insect, carefully avoiding seizing 

 it by the legs, in order to remove it from the action of its 

 aggressors. Under these conditions 1 have sometimes seen 

 autotomy take place four or five minutes after the bite. It 

 also occurred sometimes when I lifted the insect gently, 

 without shaking or squeezing it, by one of the legs upon 

 which I had observed the ants inflicting their bites a few 

 moments before. Without the least muscular contraction 

 the insect abandoned its leg and fell. 



Formic acid therefore has a very powerful action, readily 

 provoking autotomy. 



With few exceptions it was only with real difficulty that 

 I was able to bring about autotomy in adult specimens of 

 Ilhaphiderus and Monandroptera — a result produced by the 

 ants with ease, in the ease of two or three limbs at any rate. 

 The exceptions were provided chiefly by Rhaph'ulerus. In 

 certain cases, on holding the insect suspended by a liuib and 

 exerting, by means of the finger-nails, strong pressure upon 

 the median region of the femur, I have succeeded in pro- 

 ducing autotomy ; the phenomenon was reproduced in the 

 same maimer in the case of the five other legs, I have 

 succeeded in arriving at the same result by inflicting burns 

 or cuts towards the distal region of the femur. 



I met with more difficulty in the case of the Monandro- 

 ptera. Jt was the utmost 1 could do if, in a few specimens, 

 1 succeeded in causing the detachment of two or three limbs. 

 Very often I found it impossible to produce a single case 

 of autotomy in either of the two species. It is to be noted 

 that I am speaking hereof specimens observed in full vigour ; 



