314 
NATURAL HISTORY 
an upright border all round. These hurdles and floors must 
hang upon pullies, so as to be placed or taken down at 
pleasure. 
When the worms are hatched, some tender mulberry leaves 
are provided, anil placed in the cloth or paper box in which 
the eggs were laid, and which are large enough to hold a 
great” number. When they have acquired some strength, 
they must be distributed on beds of mulberry leaves, in the 
different stories of the square in the middle of the room, 
round which a person may freely pass on every side. They 
will fix themselves to the leaves, and afterwards to the sticks 
of the hurdles, when the leaves are devoured. They have 
then a thread, bv which they can suspend themselves on 
occasion, to prevent any shock by a fall. Care must be 
taken that fresh leaves be brought every morning, which 
must be strewed very gently and equally over them ; upon 
which the silkworms will forsake the remainder of the old 
leaves, which must be carefully taken away, and every thing 
kept very clean ; for nothing hurts these insects so much 
as moisture and uncleanliness. For this reason, the leaves 
must be gathered when the weather is dry, and kept in a 
dry place, if it be necessary to lay in a store. As these ani- 
mals have but a short time to live, they make use of every 
moment, and almost continually are spinning, except at 
those intervals when they change their skins, if mulberry 
leaves be d‘ /ficul t to be obtained, the leaves of lettuce or 
holly-hock will sustain them ; but they do not thrive so 
well upon their new diet ; and their silk will neither be so 
copious, nor of so good a quality. 
Though the judicious choice and careful management of 
their diet is absolutely necessary, yet there is another pre- 
caution of equal importance, which is to give them air, and 
open their chamber windows at such times as the sun shines 
The worm at the time it bursts the shell, is extiemely 
small, and of a black colour; but the head is of a more 
shining black than the rest of the body ; some days attei, 
they beam to turn whitish, or of an ash-co cured grey. 
After the skin begins to grow too rigid, or the animal is 
stinted with it, the insect throws it off, and appears clothei 
anew : it then becomes larger and much whiter, though i 
has a greenish cast : after some days, which are more 01 
less according to the different heats of the climate, ov to t lie 
quality of the food, it leaves off eating, and seems to sleep 
for two days together : then it begins to stir, and puts itself 
into violent motions, till the skin falls off the second time, 
