Silkworm from Japan. 411 
greatest importance to furnish a supply of fresh air to the eggs 
and larva, both by night and by day, except when the tem- 
perature goes down below 54°. The first days of the young 
worms’ existence require many precautions, and a large mortality 
often occurs from a neglect of these. One of the great causes of 
infant mortality is to be attributed to the shortness of the oak 
sprays given to the worms; these are generally cut at first from 
four to eight inches long, and the cut end, being placed in water, 
sucks up the liquid, which, arriving too quickly in the leaves, is 
devoured by the worms in a crude and injurious state, and pro- 
duces disease by an unhealthy chemical change. Hence the sprays, 
if short, should be changed every twelve hours, but when cut the 
length of twelve inches or more, they may be changed every 
twenty-four hours, but not ‘at a greater interval. A little char- 
coal in the water is useful to prevent decomposition. Care must 
be taken as to the bottle or vase which contains the water; if the 
neck is shallow, evaporation rapidly taking place, the level quickly 
falls, and the ends of the oak sprays are above the fluid. Hence 
the neck should be short and wide; it must also be carefully 
plugged with paper to prevent the worms creeping down and 
being drowned. To change their food, prepare first a fresh 
sample in a fresh vase of water, and then taking branch by 
branch, cut off all the stale leaves or parts of leaves that contain 
a worm and let them fall on the fresh leaves. It is sometimes 
better to cut off first the leaves and sprays that do not contain 
any worm, and having carefully examined them to see that no 
worm is there, to throw them aside and then cut up the leaves that 
hold the worms, or place the spray garnished with worms on the 
fresh food ; when they are little the worms often get in a fold or 
curl of the leaf and are then difficult to see. In this way no 
worms are touched. The fresh sprays might also be placed along- 
side of the stale ones; turning the former towards the light, the 
worms will soon leave the stale for the fresh. As the wormis in a 
state of nature feed most during the night, it is desirable to change 
the food towards evening, but it should be done by daylight, since 
by candle light the operation becomes very difficult. It is of im- 
portance always to see that sufficient foliage is provided, especially 
at night, otherwise the worms will stray away in search of fresh 
food ; worms fresh from Japan evince a greater desire for wan- 
dering than those acclimatized in France, 7. e., whose parents were 
bred in France. Also if the food be not sufficiently fresh or 
