THE SILK-WORM. 393 



mulberry leaves, and the utmost caution must be used 

 to keep them free from dirt and other insects, and 

 when the sun is upon them they must have a circula- 

 tion of fresh air. 



At the time of quitting the shell, the worm is ex- 

 tremely small, and, though black at first, it soon be- 

 comes grey ; and as it increases in size, it seems to 

 lose its relish for eating, and for two days together will 

 remain in an apparent sleep. Two or three times it 

 changes its covering, which seems to occasion it both 

 exertion and pain ; it then assumes the form of an 

 aurelia, and begins preparing its cone or ball. This 

 cone is spun from two little long bags above the intes- 

 tines, which are filled with a gummy fluid the colour 

 of marigold, which it spins out into a thread of so fine 

 a texture, that eight of them must be combined to 

 wind them from the balls, and, before the insect is 

 completely secured in this covering, it spins no less 

 than three hundred yards. The cone, when completed, 

 resembles a pigeon's egg ; and in about three weeks 

 the aurelia is changed into a moth, and forces its way 

 through its silken confinement, by repeatedly thrusting 

 its head against the pointed end. Few of these ani- 

 mals are suffered to come to this state of maturity, as 

 by forcing their passage through the cone, they injure 

 the silk ; therefore the manufacturers generally place 

 the aurelias in a very hot situation, which destroys 

 them before they become moths. 



