Silkworm from Japan. 415 
worms do not pass so readily from the stale to the fresh food as 
when the boughs are plunged into pots. Vor this reason Mons. 
Personnat prefers the long boughs in pots, or, better still, oak trees 
covered with network. 
It is well known that during the process of moulting, care must 
be taken not to disturb the worms, lest by losing the grip of their 
hind claspers, they are, as I have previously shown, unable to crawl 
out of their old skin, which lines not merely the external body, but 
also the whole of the head and jaws, the interior of the intestinal 
canal, and the spiracles. If, however, the worms are detached 
from their foothold during the first twenty-four hours, they may 
be saved by removing them apart, and presenting them with 
a piece of string to lay hold of, or the edge of a piece of 
paper, or a leaf or fine twig ; but at a later stage they are unable 
to regain their hold. I have previously pointed out a method of 
assisting these worms in their moult by the aid of a pair of for- 
ceps. During the last two stages the worms increase greatly in 
size, and therefore require a much larger proportion of food than 
when younger. This can only be estimated properly by experience. 
The worms seem to revel in being watered. ‘The best time to do 
this is mid-day and evening. It is desirable that the worms should 
obtain shade; otherwise, in hot weather, they will wander away on 
all sides from their food. For this reason, the shade of a large tree 
would be desirable asa shelter, under which to place the oak branches, 
It is especially necessary at this age that a fresh cool air should be 
abundantly supplied to the worms. Even should a frost super- 
vene, as is the case sometimes-in the month of May in England, 
they will not be injured. Mons. Personnat’s worms in 1864, at 
the end of May, were exposed to the severity of a white frost at 
an agricultural show at Evreux. They were exposed under an 
open shed, on a bough, during the night, to two or three degrees 
of frost. The worms in the morning were stiff and frozen, but 
remained firm on the sprays. On touching them they did not 
move, and the impress of the finger remained. Mons. Personnat 
thought the worms were all destroyed, but at 8 o’clock, under the 
sun’s influence the frost gave, and he was agreeably surprised to 
see his worms return to life by degrees. Halfan hour afterwards 
they were eating away as if to make up for lost time. Not one 
was lost. All his worms at home or a few miles away were ex- 
posed to the same frost without detriment. After the last change 
the skin of the larva is observed to swell out and become inflated 
as if with air, and the larva then becomes very hungry, and eats 
