mull make to put off it’s prefent form, and the ftate o f weak-
nefs and impotence under which it mud exift while in the pupa
ftate, ' it would undoubtedly chufe the moft convenient place, the
molt advantageous fituation, for the performance of this arduous
operation; one where it would be the leaft expofed to danger*
when it had neither ftrength to relift, nor fwiftnefs to avoid the
attack o f an enemy.
All thefe neceffary inftruciions the caterpillar - receives from
the influence of an all-regulating Providence, which conveys the
proper information to it by it’s own fenfations : hence, when the
critical period approaches; it proceeds as if it knew what would
be the refult of it s operations. Different fpecies prepare themfelves
for this ftate in different ways, fuited to their nature and
the length o f time they are to remain in this ftate.
When the caterpillar has attained to it’s full growth, and
the parts o f the future butterfly are fufficiently formed beneath
it’s fkin, it prepares for it’s change into the pupa ftate ; it feeks for
a proper place in which to perform the important bufinefs : the
different methods employed by thefe little animals to fecure this
ftate o f reft, may be reduced to four: i. Some fpin webs, or
cones, in which they inclofe themfelves; 2. Others conceal
themfelves in little cells, which they form under ground ; 3. Some
fufpend themfelves by their pofterior extremity ; 4. While others
are fufpended by a girdle that goes round their body. We fhall
defcribe the variety in thefe, as well as the induftry ufed in con-
ftrufiing them, after we have gone through the manner in which
the caterpillar prepares itfelf for and paffes through the pupa
ftate.
4 Preparatory
Preparatory to the change, it ceafes to take any food, empties
itfelf o f all the excrementitious matter that is contained in the in-
teftines, voiding at the fame time the membrane which ferved as
a lining to thefe and the ftomach. It generally perfeveres in a
ftate of reft and inactivity for feveral days, which affords the external
and internal organs that are under the fkin an opportunity
o f gradually unfolding themfelves. In proportion as the change
into the pupa form approaches, the body is obferved often to
extend and contra» itfelf; the hinder part is that which is firft
difengaged from the caterpillar fkin; when this part o f the body
is free, the animal ‘contraas and draws it up towards the
head; it then liberates itfelf in the fame manner from the two
fucceeding rings, confequently the infea is now lodged in the
fore part o f it’s caterpillar covering 1 the half which is abandoned
remains flaccid and empty, while the fore part is fwoln and dif-
tended. The animal, by ftrong efforts, ftill forcing itfelf againft
the fore part of the fkin, burfts the fkull into three pieces, and
forms a longitudinal opening in the three firft rings of the
body; through this it proceeds, drawing one part after the
other’ by alternately lengthening and fhortening, to llin g and
contraaing the body and different rings; or elfe, by pulhing
back the exuvia, gets rid of it’s odious reptile form.
The caterpillar, thus ftripped from it’s fkin, is what we call
the pupa, chryfalis, and aurelia, in which the parts of the future
moth are inclofed in a cruftaceous covering, but are fo foft, that
the flighted touch will difcompofe them. The exterior part of
the chryfalis is at firft exceedingly tender, foft, and partly tranf-
parent being covered with a vifcous fluid; this foon dries up,
thickens, and forms a new covering for the animal, capable of
B b relut>