LEPIDOPTERA. 35 



But it will be at once asked, What necessity could there be for the 

 caterpillars to secure the fruit from falling after each has bored a 

 hole and thus made its escape ? This question is answered bj the 

 curious circumstance that, after so securing the fruit, the caterpillars 

 return again into the pomegranate, in the hoUow interior of which 

 they undergo their transformation to the chrysalis state. 



Here, too, we may notice another interesting fact, namely, that 

 the insect has the precautionary instinct, which acts as a second 

 inducement, to make the aperture in the fruit in that stage of its 

 existence in which it is furnished with organs best adapted for the 

 purpose ; for, had the larva omitted taking this step, the consequence 

 would have been, that the poor insect, when come to its butterfly 

 state, would have been a prisoner, totally unable to make its escape, 

 being unprovided with any instrument suflS.ciently powerful to make 

 a hole in the shell ; therefore, in this butterfly, it is absolutely neces- 

 sary that a complete aperture should be left open ; and as this is a 

 circumstance which necessarily leaves the pupa exposed, it is not 

 surprising that nature should seldom resort to such a proceeding in 

 the case of internal-feeding insects. Perhaps even in this almost 

 solitary instance, we may fairly imagine that the situation is suffi- 

 ciently retired to insure them protection from many of their enemies. 

 These chrysalides are attached horizontally upon the inner walls of 

 the pomegranate, by means, first, of a patch of silk laid upon its sur- 

 face, to the centre of which the tail of the chrysalis is affixed, and, 

 second, of a slender silken thread, passing from side to side over the 

 base of the abdominal segments. As to the manner in which the 

 girthed suspension is effected after the larva has attached itself, I 

 may be allowed to make the following short extract from Messrs. 

 Kirby and Spence's third volume, p. 212. In this order of insects, 

 which have several modus operandi, some of the larvae which have a 

 short and more rigid body (as Lyccena Argus, and many more of the 

 Papiliones rurales and urhicolce), 'after having bent the head on 

 one side so as to fix one end of the thread, bring themselves into a 

 straight position, and, by a manoeuvre not easily described, contrive 

 to introduce the head under the thread, which they then bend them- 

 selves to fasten on the other side, pushing it to its proper situation 

 by the successive tension and contraction of their segments.' A 

 short time after this is effected, the skin of the caterpillar bursts, 

 and its skin is gradually sloughed off beneath the girth, until the 

 pupa is entirely naked ; the exuviae being collected at the extremity 

 of the abdomen. 



