52 
THE ART OF REARING 
thrown away. This circumstance is, therefore, 
of essential consequence, and should be noted, to 
prevent its occurrence. A little delay in the 
hatching of the silk- worms is no loss ; whereas 
it is a very serious loss, if they anticipate by a few 
days the proper period of hatching. To backen 
them when very near the time of coming forth, 
by altering the temperature, injures them mate- 
rially. (Chap. XII.) 
When the egg assumes a whitish colour, the 
worm is already formed, and with a glass may be 
seen within the shell. The eggs should then be 
covered with white paper, well pierced with a 
particular instrument made on purpose, (Fig. 11.), 
the paper cut so as to cover them all. The 
worms will appear upon this paper climbing 
through the holes : a clear muslin will do as well 
as paper. To collect the worms, small twigs of 
mulberry, with only two or three leaves on them, 
should be laid on the paper, and they should be 
increased as fast as the worms come out upon 
them, for if they do not find the leaves they get 
out of the boxes. Few worms appear the first 
day, and if the number of them is very inconsi- 
derable they should be thrown away, because 
when mixed with the later worms they would 
grow faster, and becoming mature so much sooner, 
they would only be troublesome. I prefer the 
small spray of the mulberry to the flat leaf, as I 
