





266 THE INSECT WORLD. 
This packet is more or less large according as the height ascended 
by the caterpillar is greater or less. All the turns of the thread 
which compose it are entangled. So the caterpillar does not con- 
sider it of any value; as soon as it can walk, it gets rid of it, sets 
its legs free, and leaves it behind before it has taken one or at 
most two steps. Hach time, then, costs it the cord it made use 
of to effect its ascent, but this is an expense it can always be at 
whenever it likes; it has in itself the source of the matter necessary 
for the composition of the thread, 
and it is a source in which that}! 
which was drawn off is being con- 
tinually re-supplied. Moreover, 
spinning the thread costs the} 
caterpillars little; indeed, the | 
loopers economise this thread so | 
little that most of them leave it| 
behind them wherever they go.”’ 
They are found on many trees, | 
but particularly on the oak, whose | 
foliage they often entirely devour. 
They burrow into the ground to change into chrysalides, and 
undergo all their metamorphoses in the course of the year. Others 
do not become perfect insects till the autumn, or sometimes not even 
till the following spring. A few assume the perfect state in winter. 
There are, indeed, some of these, such as the males of the Hyder- | 
mas, which fly about on the foggy evenings of November. The 
females of this genus have either no wings at all, or else only 
rudimentary ones. Two species, the Hybernia defoliaria, or Winter 



Fig. 262.—Hybernia leucophearia, male. 

Fig. 263.— Winter Moth (LHybernia Fig. 264.—Winter Moth ( Hybernia 
defoliaria), male. defoliaria), temale. 
moth, and the Cheimatobia brumata, abundant here, are very 
common in the environs of Paris. 


