AND THE CHILDREN. 
37 
In order to see some good specimens we should 
wait until evening, when we may see such as the 
Death’s-head moth, which has a figure like a death’s-head 
on its back, and Owlet moth. But I have found some of 
the finest specimens also in the day-time. 
There is one now, and it is a fine specimen too. Its 
name is Attacus Cecropia or Platysamia Cecropia. It 
is a kind of Silk-worm but its silk is of little use except 
to itself. A species of the same family, however, is cul¬ 
tivated, in California, for its silk, but the thread of the 
cocoon is not easily wound off because of the hole in it. 
The Chinese Silk-worm is cultivated more than any 
other. 
Now, what is a cocoon? I shall tell you. 
You remember what a larva is, do you not? And 
that the larva changes its skin a number ©f times. Now, 
before it changes its skin for the last time it weaves a 
silken thread about itself covering the whole body. This 
silken covering is a cocoon. The cocoon is made in the 
fall. During the whole winter and spring, for about eight 
or nine months, the pupa remains in this secluded place. 
In the month of May, sometimes earlier, the pupa excretes 
a kind of acid substance which dissolves the glue. The 
moth can then come out without tearing a thread. 
This cocoon is one continuous thread which, by care¬ 
ful work, can be spun off and woven inot silk. 
