THE SILK-WORM 
49 
THE SILK-WORM 
TT AWE yon ever visited a silkworm-nursery while the mulberry- 
A ^ trees were putting forth leaves? You probably found an im¬ 
mense room filled with trees and tiers of shelves. 
Perhaps one ounce of silkworm eggs have been used for the breed¬ 
ing. If so, you will find about forty-four thousand little black “worms” 
arranged upon the shelves. They are about a quarter of an inch long 
and housed in little nests of mulberry leaves. They are voracious 
eaters. Perhaps this is the reason) why they grow so rapidly. 
These are the larvae of the silkworm, and they appear to be very 
domestic in their habits. They remain very contented in their nests 
until, fully grown. This requires .about four weeks. During these four 
weeks they change their dress four times and devour one ton of mul¬ 
berry-leaves. 
When fully matured the silkworm larva is about three quarters 
of an inch long and is ready to spin. Branches 1 and twigs are now ar¬ 
ranged about their nests. Presently the larvae begin to show indica¬ 
tions of restlessness. The quiet little nests are forsaken. The mul¬ 
berry-leaves have no further attractions. The larvae have eaten suf¬ 
ficient for a long journey and a long nap. For several hours they 
travel from one branch to another, upj and down, back and forth. Evi¬ 
dently they are house-hunting. Finally they settle down one after 
another, and the city is quiet again. Now the spinning begins. 
The material for spinning is carried within their bodies, and also 
the spinning-wheel. This consists of two small glands situated at 
the lower end of the body. Each gland has a tube conductor extending 
through the entire body. These tubes terminate in small open canals 
on the lower lip of the mouth. 
Now the spinning-match has begun, and every spinning-wheel is 
set ini motion. A faint, buzzing noise is heard when you are attentive 
to the sound. A fine silvery thread issues from each canal, making a 
double strand. The threads harden as they come in contact with 
the air. 
They go on spinning, carrying the threads from head to foot until 
the body of the worm is entirely surrounded. Then they spin an in¬ 
side layer and still another until there is no longer space nor material 
for farther work. Now the buzzing ceases, and the little spinners nap. 
