268 Metamorphoses of Insects. 



At the present day, however, the transformations of insects 

 have lost that excess of the marvellous, which mio-ht once have 

 furnished arguments for the fictions of the ancients, and the 

 dreams of Paracelsus. We call them metamorphoses and 

 transformations, because these terms are in common use, and are 

 more expressive of the sudden changes that ensue than any new 

 ones. But, strictly, they ought rather to be termed a series of 

 developments. A caterpillar is not, in fact, a simple but a com- 

 pound animal, containing within it the germ of the future 

 butterfly, enclosed in what will be the case of the pupa, which is 

 itself included in the three or more skins, one over the other, that 

 will successively cover the larva. As this increases in size these 

 parts expand, present themselves, and are in turn thrown off, until 

 at length the perfect insect, which had been concealed in this suc- 

 cession of masks, is displayed in its genuine form. That this is 

 the proper explanation of the phenomenon has been satisfactorily 

 proved by Swammerdam, Malpighi, and other anatomists. The 

 first-mentioned illustrious naturalist discovered, by accurate dis- 

 sections, not only the skins of the larva and of the pupa encased 

 in each other, but within them the very butterfly itself, with its 

 organs indeed in an almost fluid state, but still perfect in all its 

 parts. * Of this fact you may convince yourself without 

 Swammerdam's skill, by plunging into vinegar or spirit of wine a 

 caterpillar about to assume the pupa state, and letting it remain 

 there a few days for the purpose of giving consistency to its parts ; 

 or by boiling it in water for a few minutes. A very rough dis- 

 section will then enable you to detect the future butterfly ; and 

 you will find that the wings, rolled up into a sort of cord, are 

 lodged between the first and second segment of the caterpillar ; 

 that the antennae and trunk are coiled up in front of the head ; 

 and that the legs, however difterent their form, are actually 

 sheathed in its legs. Malpighi discovered the eggs of the future 

 moth in the chrysalis of a silk-worm only a few days old, f and 

 Reaumur those of another moth (^Hypogi/mna dispar) even in the 

 caterpillar, and that seven or eight days before its change into the 

 pupa. ;j; A caterpillar, then, may be regarded as a locomotive 

 egg, having for its embryo the included butterfly, which after a 



* Hill's Swamm. ii. 24, t. 37. f. 2. 4. 

 f De Bombyce 29. 

 X Reaum. i. 359. 



