

LEPIDOPTERA. 149 
_ which elongates it; thus the split soon extends from the end or 
the commencement of the first ring as far as the other side of the 
end of the fourth. The upper portion of the body which corre- 
"sponds to these four rings is then laid bare, and the caterpillar 
has an opening sufficiently large to serve it as an egress 
through which it can entirely leave its old skin. It curves its 
‘fore part, and draws it backwards; by this movement it dis- 
engages its head from under its old envelope, and brings it up to 
the beginning of the crack; immediately upon this it raises it, 
and causes it to go out through this crack. The moment after- 
wards it stretches out its fore part and lowers its head. There 
now remains for the caterpillar nothing but to draw its hinder part 
from the old case.”’ 
This excessively laborious operation is finished in less than a 
minute. The new livery which the caterpillar has just put on is 
fresh and bright in colour. But the animal is exhausted by 
its fast, and the efforts which it has made. It requires a few 
hours in which to regain its equilibrium, and at the same time 
its former activity and voracity. 
THE CHrysaLis, oR Pupa. 
Having attained its full development, the caterpillar ceases to 
eat, as at the approach of a moult it empties its intestinal canal 

by copious ejections ; it loses its colours, and becomes dull 
and livid, and thus prepares itself to enter a new phase of its 
existence. 
Some, when about to transform themselves into chrysalides, sus- 
pend themselves to foreign bodies. Others spin a cocoon com- 
posed of silk and other substances, which secures them against the 
attacks of their enemies and the action of the atmosphere. Those 
which suspend themselves can be divided under two heads, accord- 
ing to the mode of their suspension:—l. Those which suspend 
themselves perpendicularly by the tail. 2. Those which, after 
having fixed themselves by the same part, suspend themselves 
horizontally, by means of a silk thread passed round the 
body. 
To understand the difficulty which the first of these operations 

