edase) 
IV. On the Reversion and Restoration of the Silkworm. 
By Captain Tuomas Hurvron, F.G.S., of Mussooree, 
N. W. India. (Communicated by Mr. Freperic 
Moore.) 
[Read 2nd May, 1864.] 
Introductory Remarks. 
For many years past the utmost anxiety has prevailed on the 
European Continent, and more especially in France, in regard to 
the condition of the common silkworm, known to science as the 
Bombyx Mori, the constitution of the worm appearing to be so 
thoroughly weakened and undermined, by diseases arising from a 
long and uniform course of domestication, bad nourishment and 
other prejudicial influences, as to excite the most lively appre- 
hensions lest the insect should suddenly become extinct. 
That such apprehensions are far from groundless may be seen 
in the fact that one form of disease by which the worm is attacked, 
known in France as ‘‘ la muscardine,” is said by M. Guérin- 
Ménéville annually to destroy more than one-fourth of the worms; 
and it has been clearly shown by this eminent Entomologist, and 
by several experienced cultivators of silk, that the crop has, 
within the last ten years, dwindled down to about one-half of what 
it used to be. 
Various remedies have, of course, from time to time been tried 
for the purpose of arresting the progress of disease, sometimes 
with partial and temporary effect, but more generally without any 
success at all. 
In consequence of these maladies, and their inability to arrest 
them, the French, with prudent and praiseworthy foresight, are 
using every possible means to introduce and acclimatize other 
species, which may, in some measure, fill the commercial void 
which would be created by the loss of the common silkworm. 
Under these circumstances it occurred to me, that while assisting 
our continental neighbours in the introduction of such wild species 
as occur within our Western Himalayan forests, I might as well 
at the same time endeavour if possible to reclaim and restore to 
health the most valuable species of the whole; and, consequently, 
for several years past I have studied and experimented upon the 
Bombyx Mori and its domesticated congeners, with a degree of 
success which I now purpose to unfold. 
