266 Metamorphoses of Insects. 



and a very considerable number (the tribe of locusts, cockroaclies, 

 bugs, spiders, (fee.,) not only greatly resemble the perfect insect in 

 form, but are equally capable with it 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 pupse 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 Heiniptera^ which resemble the perfect insect, 

 except in having only the rudiments of wings, and to which the 

 name of semi-complete pupse was applied by Linne, and that of 

 semi-nymphs by some other authors. There is still a fifth kind of 

 pupse, 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 terra pupa^ we refer indiffer- 

 ently 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 casecl-mjmph, on the other hand definitely pointing 

 out the particular sort of pupa meant : just as in Botany, the com- 

 mon term pericarp applies to all seed-vessels, the several kinds 

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



The envelope of cased -nymj^hs, which is formed of the skin of 

 the larva, considerably altered in form and texture, may be con- 

 veniently called the pupariuni ; but to the artificial coverings of 

 dilTerent kinds, whether of silk, wool, or earth, &c., which many 

 insects of the other orders fabricate 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 enclosed 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 apterious species) furnished 

 with wings, capable of propagation, and often under a form 



