It is called o b te c ta , difguifed or Ihrowded, when the infect is
enveloped in a cruftaceous covering, confiding of two parts, one
o f which furrounds the head and thorax, the other the abdomen.
It is termed incom pleta , when the pupa has perceptible
wings and feet, but cannot move them.
'Semicompleta ; thefe can walk or run, but have only the
rudiments of wings. The difference between the pupa and the
larva of this clafs is very inconfiderable, as they eat, walk, and
aft, juft as they did in their primitive ftate; the only remarkable
difference is a kind o f cafe, which contains the wings that are to
be developed in their fly ftate.
C o m p l e t a ; thofe defigned by this name take their perfeft
form at their birth, and do not pafs, like other infefts, through
a variety of ftates, though they often change their fkin.
It is a general rule, that all winged infefts pafs through the
larva and pupa ftate before theyaffume their perfeft form: there
are alfo mfefts which have no wings, and yet undergo fimilar
transformation, as the bed bug, the flea, &c. Other infefts,
which have no wings, and which always- remain without them,
never pafs through the pupa ftate, but are fubjeft to confiderable
changes, as well with refpeft to the number as the figure o f their
parts; thus mites have four pair o f feet, and two fmaller ones at
the fore part of the body, near the head ; yet fome of thefe are
bom with only three pair o f feet, the fourth is not perceived till
fome time after their birth.* The figure of the monoculus
quadri-
# De Geer Memoires pour fervir a l’Hiftoire des Infe&es, tom. i. p. 154.
quadricornis of Linnaeus (Fauna Suecica, edit. Stockholm, 1761,
No. 2049). changes eonfiderably after it’s birth.* The julus is
an infeft with a great number o f feet, fome fpecies having an
hundred pair and upwards. M. De Geer has given a defeription
o f one- with more than two hundred pair,+ and yet thefe at their
birth have only three pair, the reft are not perceived till fome
time after.
We fhall now return to the caterpillar, and take notice o f the
care and provifion it makes to pafs from the larva ftate into that
of the pupa, orchryfalis ; which is, in general, a. ftate of imper-
feftion, inaftivity, and weaknefs, through which the infeft,
when it has obtained a proper fize, muff pafs ; and in which
it remains often for months, fometimes. for a whole year, ex-
pofed, without any means of efcaping, to every event; and in
which it receives the neceffary preparations for it’s perfeft ftate,
and is enabled once more to appear upon the tranfitory fcene of
time. During it’s paffage from one ftate-to the other, as well as
when it is in the pupa form, the microfcopical obferver will find
many opportunities, o f exercifinghis inftrument.
The tranfitions o f the caterpillar from one ftate to-another, are
to it a fubjeft of the moft interefting nature ; for in paffmg
through them, it often, runs: the rilk of lofing, it s life, and life is
the greateft. boon the Creator can beftow ; it is ever accompanied-
with a degree of delight proportioned, to the ftate in- which the-
creature cxifts, and the ufe it makes of the gift it has received. I f
die caterpillar, could therefore forefee the efforts and exertions it
mu ft
* De Geer Memoires-pour fervir a4JHiftoire des- Infe£tes, tom. 1» p. 155..
t Memoirefcties Sjavans etrangers, tom. 3, p. 6.x.