•place, they form with their hinder feet a poliflied cavity, in this
they lie for fome time immoveable; after, which, by voiding ex-
crgmentitious fubftances, and by ithe ■ evaporation of humidity, it
becomes thinner and fhorter,thelkin more furrowed and wrinkled,
fo that it foon appears as if it was flarved by degrees. I f it be differed
about this, period, the head, the belly, and the thorax, may
be clearly diftinguiftjed. While fome external and internal parts
are changing by a flow accretion, others are gently diftended by
the force of the blood and impelled humours. The. body contracting
itfelfl while the blood is propelled towards the foreparts,
forces the Ikull open in three parts, and the fkin in the
middle of the back is feparated, by means o f an undulating motion
o f the incifions o f the; back ; at tftefame 'time..the eyes, the horns,
the lips, &c. call their exuvia, During this operation,
a thin watery humour is diffufed between the old and new
Ikin, which renders the reparation ealier. The procefs going on
gradually, the'worm is. at laft difengaged from it’s fkin, and the
limbs and parts are, by a continual unfolding, transformed into
the pupa ftate; after which, , it twills and compreffes the exuvia
by the fundament, and throws it towards the hinder part under
the belly. The pupa is at this time very delicate, tender, and
flexible; and affords a mofl aftonifhing appearance to art attentive
obferver. Swammerdam thinks it is fcarce to be equalled among
the wonders, which are difplayed in the infedl part o f the creation;
in it the future parts of the beetle are finely exhibited, fo difpofed.
and formed, as foon to be able to ferve the creature in a. more
perfect ftate of life, and to put on a more elegant form.
The
The pupa* of this infeft weighs, a little after it’s change,
much heavier than it does in it’s beetle ftate; this is alfo the cafe
with the pupa- o f the bee and hornet- The latter has been
found to weigh ten times as much as the hornet itfelf ■ this is
probably occafioned by a fuperabundant degree o f moifture, by--
which thefe infedls are kept in a ftate o f inaftivity (a kind of preternatural
dropfy) till it is in fome meafure difftpated; in proportion
as this moifture is evaporated, the fkin hardens and dries;
fome days are required to fweat off this fuperfluous moifture.
I f the fldn is taken off at this time, many curious circumftances-
may be noted ; but what claims our -attention molt is,■ that the
horn, which is fo hard in the male beetle w hen in a ftate of maturity,
that it will bear to be fharpened againft agrindftone.t in
the pupa ftate is quite faft,'and more like a fluid titan a folid
fubftance.
How long’ die fcene: o f mutation continues is not known;
fome remain during the whole winter, more particularly thofe
who quit the larva ftate in autumn, when a fudden cold
checks, their further operations, and confequently they remain
without any food for feveral months. • Some fpecies o f the
beetle tribe go through all the ftages'of their exiftence in a feafon,
while others employ near four years in the procefs, and live as
winged infefts a year.
When the proper time for the final change arrives, all the
ntufcular. parts grow flrong, and arerthus more able to fhake off
D d 2 their
•* Swarmr.e dam’s Bo k of. Ni tu.e, p. 144*
t Mou-fFet, p. i^a.