Silk-producing Bombycide. 319 
mountains, from the neighbourhood of Delia, at about 2,000 feet 
of elevation up to 7,000 and even 8,000 feet. It does not appear 
to occur in Nipal, but ranges westward from about Kemaon. 
This worm is double-brooded, and yields two crops of silk in the 
year ; this is of the very best quality, but unfortunately the worm 
is so erratic and intractable, that hitherto all attempts to domesti- 
cate it have proved abortive; it will not remain in the feeding 
trays, like the Chinese worms, but wanders away until the brood 
is lost. The only method of rearing it is to leave it at full 
liberty on the trees, where it remains perfectly quiet and con- 
tented, but has so many enemies to contend with, in the shape of 
birds, flies, bugs and wasps, as to render a crop of silk very 
precarious and almost unattainable, without constant watching 
and expense, which renders the crop unprofitable. 
As previously stated, I discovered this species at Simla in the 
autumn of 1837, on the wild forest mulberry, and again after the 
campaign in Afghanistan, at Mussooree in 1842, at which time 
I sent it to Mr. Westwood, in England. 
The wild mulberry-tree of the North Western Himalaya 
usually comes into leaf about the first week in March, but of 
course this is in a great measure dependent upon the situation, 
elevation and temperature of the season. 
The eggs of this silkworm are firmly attached to the bark of 
the tree, sometimes on the trunk, but more generally on the 
underside of the branches, where they remain spread out in 
clusters and exposed all the winter to the action of the frost, but 
where they are at the same time protected from the rain and 
snow, so as to run no risk of being washed off by the dissolving 
of their agglutinating gum. 
The colour of the egg is a pale straw-yellow, which, unlike the 
eggs of the Chinese races, is retained to the last. The egg is 
considerably larger than those of 6, Mori. The young worm is 
disclosed from the egg a few days after the opening of the leaf- 
buds; the hatching is, however, very irregular and continues 
sometimes even up to the end of April, although this is generally 
dependent upon the situation of the tree. 
In some seasons these worms are so numerous that the trees 
are completely denuded of every leaf by the middle of May, and 
in such cases the worms, after gnawing off all the leaves which 
envelope the cocoons already formed, are compelled to descend 
from the tree and spin among the leaves of the neighbouring shrubs 
and bushes, while many that are still immature necessarily die of 
hunger, or fall a prey to birds. The trees that have been thus 
denuded speedily put forth fresh leaves, to be in due time consumed 
