METAMORPHOSES. 71 



of eating and moving. As these insects, however, cast their skins at 

 stated periods, and undergo changes, though slight, in their external and 

 internal conformation, they are regarded also as being subject to metamor- 

 phoses. These pupae may be subdivided into two classes: first, those 

 comprised, with some exceptions, under the Linnean Aptera, which in 

 almost every respect resemble the perfect insect, and were called by Linne 

 complete pupae; and, secondly, those of the Linnean order Hemiptera, 

 which resemble the perfect insect, except in having only the rudiments of 

 wings, and to which the name of semi-complete pupae was applied by 

 Linne, and that of semi-nymphs by some other authors. There is still a 

 fifth kind of pupae, which are not, as in other instances, excluded from the 

 skin of the larva, but remain concealed under it, and were hence called 

 by Linne coarctate pupae. These, which are peculiar to flies and some 

 other dipterous genera, may be termed cased-nymphs. 



When, therefore, we employ the term pupa, we refer indifferently to 

 the third state of any insect, the particular order being indicated by the 

 context, or an explanatory epithet. The terms chrysalis (dropping 

 aurelia, which is superfluous), nymph, semi-nymph, and cased-nymph, on 

 the other hand definitely pointing out the particular sort of pupa meant: 

 just as in Botany, the common term pericarp applies to all seed-vessels, 

 the several kinds being designated by the names of capsule, silicle, &;c. 



The envelope of cased-nymphs, which is formed of the skin of the 

 larva, considerably altered in form and texture, may be conveniently called 

 the puparium : but to the artificial coverings of different kinds, whether 

 of silk, wood, or earth, &c. which many insects of the other orders fabri- 

 cate for themselves previously to assuming the pupa state, and which 

 have been called by different writers, pods, cods, husks, and beans, I shall 

 continue the more definite French term cocon, anglicized into cocoon. 



After remaining a shorter or longer period, some species only a few 

 hours, others months, others one or more years, in the pupa state, the en- 

 closed insect, now become mature in all its parts, bursts the case which 

 enclosed it, quits the pupa, and enters upon the fourth and last state. 



We now see it (unless it be an apterous species) furnished with wings, 

 capable of propagation, and often under a form altogether different from 

 those which it has previously borne — a perfect beetle, butterfly, or other 

 insect. This Linne termed the imago state, and the animal that had 

 attained to it the imago ; because, having laid aside its mask, and cast off 

 its swaddling bands, being no longer disguised or confined, or in any res- 

 pect imperfect, it is now become a true representative or image of its 

 species. This state is in general referred to when an insect is spoken of 

 without the restricting terms larva or pupa. 



Such being the singularity of the transformations of insects, you will 

 not think the ancients were so wholly unprovided with a show of argu- 

 ment as we are accustomed to consider them, for their belief in the possi- 

 bility of many of the marvelous metamorphoses which their poets recount. 

 Utterly ignorant as they were of modern physiological discoveries, the 

 conversion of a caterpillar into a butterfly must have been a fact sufficient 

 to put to a nonplus all the sceptical oppugners of such transformations. 

 And however we may smile, in this enlightened age, at the inference drawn 

 not two centuries ago by Sir Theodore Mayerne, the editor of Mouffet's 



