HISTORY OF THE SILK-WORM. 



After an interval of from 15 to 20 days repose, the 

 moth ejects from its mouth a liquor, which moistens 

 the gum and dissolves the adhesiveness of the texture 

 of the ball, and by frequent motions of its head, it 

 loosens and forces aside the filaments, without sunder- 

 ing a single silken thread, until it reappears, transforrr- 

 ed to a large butterfly, of a greyish white color, with 

 four wings, two eyes, and two black feathery horns or 

 plumes. Unshrouded, in this its last and perfect form, 

 both male and female, they come forth to the light of 

 day : from this time they take no visible food to the day 

 of their death. 



They commence laying their eggs in twenty-four or 

 thirty-six hours after leaving the cocoon. Each female 

 usually lays four hundred eggs, which firmly adhere to 

 the paper, on which they are arranged in a handsome 

 and circular form. In a few days after, their multifa- 

 rious labors being ended, the insect dies. 



The silkworm remains in the chrysalis state a length 

 of time corresponding with the temperature of the cli- 

 mate. In England they remain 30 days. In France 

 21, in Spain and Italy 18 or 20; in the United States 

 about the same, and in India but 11 days. 



The silk-worm, like other caterpillars, is a cold- 

 blooded insect, its temperature that of the atmosphere 

 in which it breathes. Sudden changes from cold to 

 heat are highly injurious ; yet it has been found that the 

 silk-worm is capable of enduring a great degree of heat 

 if uniformly maintained. Such a degree they must at 

 times endure in their own native forests, not only of 

 light, but also of heat, with no shelter from the scorch- 

 ing sun but the shadow of a leaf. Yet in no case is a 

 due degree of warmth more needful, than while the 

 insect is forming the cocoon. If at any time while they 

 are performing this most important labor, they are per- 

 mitted to suffer from cold, they cease from their labors, 

 and remain inactive, or move but slowly, as may be dis- 

 cerned while the cocoons are yet transparent. It has 



