118 On the Regenerative Surfaces in the Phasmidae. 



immediately. It is not so when the insect is a somewhat 

 large one and is attacked by a Calotes of small size. In most 

 cases the latter can only seize its prey by a limb. Then, by 

 little abrupt and rapid movements, performed by relaxing a 

 very little and then immediately tightening the grip of its 

 jaws, which advance, so to speak, little by little, mounting up 

 the limb, it finally reaches the body itself. I was never able 

 to discover that its teeth severed the limb. They merely 

 plant themselves more or less deeply in the chitinous sheath. 

 The insect struggles and clings to the nearest objects by 

 means of the claws with which the tarsi are terminated. 

 This results in very severe strains on all the limbs, but 

 especially on the leg which is seized. Not infrequently when 

 the teeth reach the upper half or upper third* of the femur 

 they may produce autotomy by breaking, if they penetrate 

 deeply enough through the chitinous sheath. In certain cases, 

 after having thus abandoned a limb, the insect, if upon a 

 branch, allows itself to fall to the ground. In this manner 

 it sometimes succeeds in hiding itself in the grass and in 

 throwing its enemy off the scent. But in most cases it does 

 not act thus, and confines itself to fleeing before the lizard. 

 The latter speedily catches it up and renews its tactics, which 

 in most instances end in the death of the Orthopteron. 



When — which is of somewhat rare occurrence — the Calotes 

 has only been able to seize the terminal extremity of the 

 limb, the result, thanks to the relative fragility of this region, 

 is the removal of a portion or of the whole of the tarsus, 

 either by a pretty clean cut or by being pulled off. These 

 mutilations must have contributed to the development of the 

 regenerative faculty possessed by the tarsus and the lower 

 third of the tibia ; for the muscular fibres which move the 

 joints of the tarsus have their attachments precisely in this 

 portion of the tibia, and are subjected, beyond doubt, to strains 

 and lesions, constituting a mode of excitation which is suffi- 

 cient to explain the cases of regeneration exhibited by this 

 lower third of the tibia. 



We must not take any account of ants, whose bites can 

 only provoke autotomy, and never mutilations of other kinds. 

 The action of these bites is a purely chemical one, and could 

 only have succeeded in manifesting itself at the outset of the 

 period at which the special disposition which ensures spon- 

 taneous amputation had been subjected, in course of time, to 



* The only region at which it is possible to provoke autotomy by 

 cutting, pinching, or breaking. 



