FAMOUS SPINNERS 
115 
‘ foundation/ which in this case is a network to 
hold the cocoon. One strand comes from each 
spinneret, and the two strands are joined to¬ 
gether. But it is quite impossible to see how this 
joining is done, even with the most powerful 
magnifying glass. At first the spun thread is as 
soft as jelly, but it hardens quickly on being ex¬ 
posed to the air. The caterpillar seems to force 
the silk out by contractions of its body, and even 
after the network is finished and the caterpillar 
has begun to wind itself into a cocoon in the cen¬ 
ter, one may know that the work is still going on 
by a soft little sound made by the machinery of 
the tiny silk manufacturer. In twenty-four 
hours the spinner is hidden from sight, but it is 
still busily at work. 
“ For three days and nights the tiny silk fac¬ 
tory runs without ceasing, and then behold! a 
beautiful light-colored silken house nearly as 
large as a pigeon’s egg. There is no door or win¬ 
dow. The little occupant will make a door in 
one end when it is ready to come out. Because 
the making of this door cuts the silk so that it 
cannot be wound, only those cocoons which are 
needed to provide moths for future egg laying 
are left to develop. A difference in the shape and 
size of the cocoons denotes the sex of the creature 
within: the females spin large plump cases, while 
the work of the males is much smaller, with 
