118 THE ESCAPE OF THE MOTH. 
from without can get in; while in the real trap, 
the poor little mouse can get in quickly enough? 
hut can never get out again. 
The caterpillar is not satisfied even when it has 
set its sharp spikes round the "doorway. It spins 
a little dome below the opening, and when it be¬ 
comes a chrysalis, it hangs suspended beneath it. 
In due time the moth makes 
her appearance, and escapes 
through the trap-door, the 
wires closing after her, so 
that no one can tell she is 
gone. 
There is a story told of a 
person who kept a cocoon of 
the emperor moth in a box, 
and one morning, was very 
Chrysalis of Emperor moth, much puzzled to find the 
moth fluttering about beside it. He thought she 
must have got out by magic, for the cocoon looked 
exactly as it did before; and it was not until 
he cut it open and discovered the trap, that the 
mystery was solved. 
The time that a chrysalis lies in its cocoon is 
very variable, and depends on the size of the 
moth, and the season of the year. As, for in¬ 
stance, if the cocoon is spun in the autumn, the 
chrysalis will remain stationary all the winter; 
