SILK-WORMS. 
25 
cepting these cases, there are few silk-worms that 
have in the course of their lives travelled beyond 
the space of three feet. 
The time employed by the silk-worm in our 
climates, from the period of hatching until it de- 
posits the seed and dies, is about sixty days. 
The greater the degree of heat in which it is 
reared, the more acute are its wants, the more 
rapid its pleasure, and the shorter its existence. 
From the moment of the birth of the silk- 
worm until the gathering of the cocoons, I 
reckon, in my establishment, about forty days. 
Sometimes an unfavourable season obliges us to 
prolong the existence of the insects for some days, 
as will be seen hereafter, to enable them to digest 
and properly work the food necessary for them. 
If the artificial heat were great and uninter- 
rupted, the cocoons might be gathered in less 
than five-and-thirty days. Great heat shortens 
the time employed in rearing silk- worms, but it 
may also easily become their bane, if it be not 
accompanied by most constant and attentive care. 
f 
c 
