METAMORPHOSES. 35 
external and internal conformation, they are regarded also as being subject 
tometamorphoses. These pupa 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 
Linné complete pupx ; and, secondly, those of the Linnean order Hemi- 
ptera, which resemble the perfect insect, except in having only the rudi- 
ments of wings, and to which the name of semi-complete pupe was 
applied by Linné, and that of semi-nymphs by some other authors. There 
is still a fifth kind of pupe, which are not, as in other instances, excluded 
from the skin of the larva, but remain concealed under it, and were hence 
called by Linné coarctate pups. 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 con- 
text, or an explanatory epithet. The terms chrysalis (dropping aurelia, 
which is superfluous), xymph, 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 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 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 Linné termed the imago state, and the animal that had 
attained to it the imago; because, haying laid aside its mash, and cast off 
its swaddling bands, being no longer disguised or confined, or in any respect 
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 argument as 
we are accustomed to consider them, for their belief in the possibility of 
many of the marvellous 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 cen- 
turies ago by Sir Theodore Mayerne, the editor of Mouffet’s work on 
insects, “that if animals are transmuted so may metals", it was not, in 
1 Epist. Dedicat. 
D2 
