Restoration of the Silkworm. 171 
breath of wind, not a change of temperature, must pass over these 
tender beings, for fear the destroying angel should stretch forth 
his hand and ruthlessly exterminate the whole. But common 
sense would fain inquire,—‘Is the worm naturally of so tender a 
constitution that no change must be suffered to come nigh its 
dwelling? If so, how did the insect contrive to brave the storms, 
and outlive the daily changes of temperature, even from day to 
night, when exposed upon the trees in its own native and northern 
mountain climate? Nay why was such change from day to night 
ordained if it were to prove injurious to organic structures ?”’ 
I have proved, however, at Mussooree, that the worms of 
different species, even in their present debilitated state, are not so 
delicate as it has hitherto been the fashion to suppose, and have 
successfully reared great numbers of worms that were night and 
day exposed to every change of temperature, to every gale that 
blew, and above all to the constant moisture of the mists which 
were permitted to pass through the room, saturating leaves and 
trays, and causing the worms themselves to sparkle through the 
moisture deposited upon them. Yet notwithstanding this rough 
treatment no deaths occurred, no particular diseases showed them- 
selves, and the cocoons produced were pronounced by competent 
judges to be good and the silk of the best quality. 
They have likewise been successfully reared in France in the 
open air, and the cocoons are pronounced to be superior to 
those reared within the house. 
And yet, after all, seeing that the constitution of the insect has 
been completely destroyed, what wonder if it be found unable to 
bear up successfully against the sudden changes of temperature 
of a foreign climate? ‘Too great a degree of heat,—an improper 
system of feeding,—the exclusion of fresh air from the rooms, 
and, above all, the long-continued system of breeding in and in 
with debilitated stock, have at length reduced the worm to the 
condition of a leper, and have banished from its skin every trace 
of those colours with which Nature had originally ornamented it. 
Even in Europe it has been found that heat is inimical to its 
health, for not only in Italy is the best silk produced in the 
mountainous parts of Piedmont, but M. Guérin-Ménéville, in a 
tour made in 1858 through France and Italy, likewise declares 
that it is in “those elevated localities where the vine and the 
mulberry escaped disease, that the worm was found to enjoy the 
best health.” 
This indefatigable naturalist also notices a custom which has 
