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supposing the young caterpillars to be supplied with the 
requisite amount of food, and all necessary attention paid to 
them. It must not, however, be supposed that every egg 
will produce a caterpillar and cocoon ; many casualties will 
necessarily occur. The common Silkworm, for instance, 
loses on an average in each brood from one- fourth to one- 
third of the original number. Taking the highest of these 
as the proportion for the Assam Silkworm, although this 
species is more healthy, and by making the deduction at 
the outset, it leaves one hundred couples as the first produce 
of the original pair. Proceeding in this manner with the 
calculation, it will be found that at the end of the year the 
descendants of this pair will have reached no less a number 
than ten thousand million million couples, and that the eggs 
of these latter will amount to the enormous sum of two 
million million million. 
The author calculates that 3,300 empty cocoons are amply 
sufficient to yield one pound of silk, but he assumes that 4,000 
would be required, and this would give 500 billion pounds of 
silk as the entire product of one couple, and, assuming the 
population of Germany at 45 millions, this calculation at 
the year's end would allow more than 10,000,0001bs. to 
each individual, and many a poor wretch, he says, who now 
shivers in the winter's cold, would have reason to be grateful 
to the first pair of moths for a warm and comfortable pro- 
tection against the inclemency of the season. In making 
this statement, however, Herr Kaufmann merely does so to 
show the moderate estimate he has arrived at of the prolific 
powers of the Assam Silkworm. He does not suppose for a 
moment that it would be possible, or even expedient, to rear 
such an enormous number, as neither land nor labour could be 
spared to furnish the immense supply of vegetable matter 
which would be required for that purpose. The numbers 
reared must be regulated by the demand for the material, and 
