148 NORTH AMERICAN INSECTS. 
. 
lucrative amusement, as well as for the purpose of furnish- 
ing accurate data to those who are interested in the history 
of the raising of silk-worms for commercial purposes, we 
shall enter still more into its details. 
An ounce of the eggs of the silk-worm moth contains 
about forty thousand caterpillars, which, if all live, will 
produce one hundred pounds of floss-silk. This number of 
caterpillars will consume about a thousand pounds of leaves, 
to furnish which about sixty white mulberry-trees will be 
required. If these trees are properly cultivated they should 
be planted about six feet apart, and after they are well 
grown need very little care. 
From these data it may be seen how easy and how profit- 
able is this species of husbandry; and yet so little silk has 
hitherto been produced in the United States that we have 
imported it from Italy, France, and China. It seems al- 
most incredible, but it is nevertheless true, that during the 
year 1855 over twenty-five millions of dollars’ worth of silk 
was imported into this country from the above-named places. 
We give the exact figures of the imports, viz. : 
Of raw milk aie eae ee $751,623 
Of mmnufactived el esii25s4ecaG ht wher ieee 24,916,356 
Malsing ian valk ites teiieannains oaeippbe cabantink $25,667,979 
Italy, scarcely larger than our State of Florida, exports 
annually raw silk to the amount of $500,000, and manu- 
factured silk to the amount of $13,800,000; making in all, 
for this one article of commerce, $14,300,000. 
Even in the small peninsula of the Crimea, silk-culture 
is carried on to a very great extent, and in many places by 
the Tartars, Greeks, and Armenians. We recollect making 
a July excursion in that romantic country thirty years ago, 
and our visit to one of the numerous silk establishments 
there is still treasured up among the delightful incidents of 
early travels. Before the break of day we left Sudak, on 
the shore of the Black Sea, directing our way toward the 
