20 
THE ART OF REARING 
shaken, the caterpillars that drop off must be 
collected and burnt : but there is nothing so effi- 
cacious as destroying them in the winter. 
The cabbage caterpillars may be taken at night 
with artificial light. 
I have, doubtless, in this chapter said more 
than the subject of this work allows, but I 
thought it might be useful to avail myself of this 
opportunity of making a class of insects, so much 
complained of, more generally known, in which 
class is ranked the silk-worm, that, in opposition 
to its species, is one of the principal sources of 
our wealth. What I have said may also prevent 
some repetitions in the course of this work. 
CHAPTER II. 
OF THE SILK-WORM. 
We have seen (Chap. I.) that, notwithstanding 
the war waged against caterpillars by men, by 
animals, and by seasons, in our climate ; they yet 
elude that destruction which threatens them so 
often. 
It is not thus with the silk-worm. In these cli- 
mates, (France and Italy), it could not thrive, 
nay, it could not exist through a season even, if 
