82 ON THE CULTURE OF SILK. 



may be protracted by cold or other bad weather, or by irregular 

 or scanty feeding. I have known, says Cobb, the period 

 retarded to sixty days. These changes should be noticed. 

 When about to change their skins, they hold up their heads and 

 appear to sleep. As this condition approaches they eat but 

 little and should be fed accordingly. As soon as the change is 

 completed, they become active and voracious. 



Apparatus, &fc. — The worms being hatched suitable tables 

 or shelves must be prepared for their reception. These should 

 be so constructed and placed, that birds, fowls, rats, mice, spiders 

 and ants, cannot gain access to them. To prevent this, nail 

 lathes across the windows and let the shelves be supported on 

 small posts or legs which rats and mice cannot climb, besmeared 

 with tar or other substance, over which spiders and ants cannot 

 pass, and placed in the middle of the room. These shelves 

 may be made of rough or planed boards, covered with paper, or 

 what is better, of wicker-work, — that is, a frame filled with small 

 rods, (about one quarter of an inch apart,) these to allow the 

 free circulation of air and permit the litter and excrements to fall 

 through to a sliding shelf placed below it. By this apparatus 

 nearly all the filth may be cleared away without disturbing the 

 worms. Care must be taken, however, while the worms are 

 small, not to throw them away with the litter, as some of them 

 may fall through with it. The most simple and best contrived 

 shelves, are low tables with legs about a foot long at the corners, 

 set one upon another. In making these tables the lower one 

 should be about six inches longer and broader than the one next 

 above it, so as to break the fall of such worms as happen to 

 tumble down. A square foot will afford sufficient space for fifty 

 full grown worms. In the first age the worms will require only 

 one-twentieth of this space, in the second age one-tenth, in the 

 third one-fifth, and in the fourth one-half The mean width of 

 the shelves should be about two and a half feet, of any length 

 that will admit of a free passage around them. 



Food, S^c. — Mulberry leaves are said to consist of five 

 different substances. 1st, the solid fibrous substance : 2d, the 

 coloring matter: 3d, water: 4th, a sweet mucilaginous or sac- 



