515 
transfohmatiosi op insects. 
' f silkworm, previous to its chrysalis state, casts 
times. The first skin is cast on the 10th, 11th, 
**^''ttd • according to the nature of the season ; the 
five or six days after ; the third in five or six days 
^'’8 fouith and last in six or seven days after the 
\fl.. This changing of skin is not only common to all 
but to every insect whatever. Not one of them 
Se perfection without casting its skin at least once or 
Site 3 fter it is cast, preserves so entirely the 
kc.t. the caterpillar in its head, teeth, legs, colour, hair, 
S ‘t is often mistaken for tlie animal itself. A day ot 
^jp 1 this change h.ippens, caterpillars take no foodj 
Slgj,*® their former activity, attach themselves to a par- 
it^t ttud bend their bodies in various directions, till, 
\ ’ ‘Jt^y escape from the old skin, and leave it behind 
The inteslinnl t>f caterpillars is composed ot 
tubes, the one inserted into the other : the 
Sgyube is contpact and fleshy ; but the internal one is 
Nth^ transparent. Soma days before caterpillars change 
V state, they void, along witli their excrement, 
tr«tl T which lined their stomach .and intestines. 
Jittjjjp ,8tit to pass into the chrysalis state, which is a state 
they select the most proper places and modes 
themselves from their enemies. Some, as the 
%if and many others, spin silken webs or cords round 
which completely disguise the animal form. 
'■k'6 plants upon which they formerly fed, and 
lljj 'einselves in little cells which they make in the eartli. 
![ worm abandons the water upon the approach 
’I'^tamorphosis, retires under the earth, where it is 
\ a chiy'salis, and, after a certain time, bursir 
N Of ®®einingly inanimate condition, and appears in die 
^st ^ ® winged insect. Thus the same animals pass thp 
^°“g8.st period of their existence in tlie water, 
"^'Icr the earth, and the third and last in the air- 
j5!o ®'*ferpili;irs, when about to change into a chrysalis 
..M '^heir bodies witli a mixture ot cariii and ot silk, 
themselves in the loose soil. Others incrust 
> with a silky or glnfinous matter, whfeli they^ush 
tljeir mouths, without spinning it into threads. 
*^®tire into the holes of walls or decayed trees, 
^ttspend themselves to the twigs of trees, or to oriier 
