Restoration of the Silkworm. 157 
health of the insect. Were the white or the yellow colour to 
remain permanent in all climates and temperatures, the fact might 
reasonably be regarded as a specific character, but where, as in 
the above observations, we perceive these colours to be dependent 
upon temperature, we are compelled to regard the change as 
entirely dependent upon the state of health. 
Thus heat, by causing debility, undermines the constitution, 
and gradually changes the natural colours, of both the insect and 
the silk secreted by it, into a sickly white, while a restoration to 
a cooler climate will, under proper management, restore the 
colours to their natural shade, by imparting vigour to the droop- 
ing insect. 
Deterioration proved. 
Those who possess any real knowledge of the subject under 
discussion will, [ am fully aware, require no further proof of the 
worm’s deterioration than has already been furnished above ; yet 
as there are not wanting some pretended savans, whose private 
interests prompt them to conceal as much as possible the 
maladies under which all our worms are labouring, 1 shall 
proceed yet further to show, even from their own arguments, 
how very little they really know upon the subject. 
Common sense will at once point out that a worm imported 
from the northern provinces of China will not long maintain its 
vigour in any part of the hot lowland provinces of India, and 
indeed this is fully shown by one cultivator proposing to preserve 
the eggs of Bombyx Mori by sending them from the Punjab to 
the mountain station of Durrumsala, as well as by the fact that 
Jaffer Ali of Mooltan invariably preserves his in a cool under- 
ground chamber or tykhana. 
It is evident from this, that even the heat of the Punjab is far 
greater than the egg can bear, and if it be inimical and destructive 
to the egg, it will undoubtedly be equally so to the insect in every 
other stage. The loss annually sustained by the cultivator Jaffer 
Ali, even when the eggs are kept in the dykhana, is said to be 
‘from a fourth to a third,” the heat (even under ground !) drying 
up the eggs without hatching the worms!* If this can be called 
successful cultivation then no one need despair ! 
From this admission it is clear that what actual disease effects 
in France, where “ /a muscardine” is said annually to destroy more 
than one-fourth of the worms, is effected by heat, even in an 
* Powlett’s Report in Proceedings Agricult. Soc. of India, 9th July, 1862. 
