24 HISTORY OF INSECTS. 



those who purpose keeping silk-worms for the sake of pro- 

 fit, to defer the hatching of the eggs until the mulberry-trees 

 are sufficiently forward to ensure a constant supply of food. 

 The usual time for the hatching of silk-worms' eggs in this 

 country is about the 12th of May, but a fortnight later is 

 much better ; for at that time the mulberry -trees have not 

 generally put forth their leaves, and great difficulty contin- 

 ually occurs in procuring food : for, as far as we have yet 

 learned, no other food than mulberry-leaves affords to silk- 

 worms wholesome nutriment ; lettuce, dog-wood and black- 

 currant leaves have been often tried, but without success. 



It maybe remarked that in winding off the silk, when the 

 single threads of half a dozen cocoons are found, they may 

 be guided with one hand on a small reel constructed for the 

 purpose, which may be turned with the other hand, the co- 

 coons at the same time floating on a basin of warm water. 



