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earth at the bottom should be kept damp. To 

 accompb'sh the latter object, I keep a thick 

 layer of moss upon the surface, which I take 

 out occasionally (perhaps once a week in hot 

 weather, and once a fortnight or three weeks in 

 Winter) and saturate completely with water, and 

 return it to its place : this keeps up a sufficient 

 supply of moisture, without allowing the earth 

 to become too wet, which is equally injurious 

 to the pupce, with too much aridity. By num- 

 bering the cells, and keeping a register corres- 

 ponding with the numbers, the history of any 

 particular larva or brood may be traced." 



It is very desirable (if it can be accomplished) 

 to keep each kind of caterpillar by itself, as 

 some species will devour others, and even their 

 own kind, if not well supplied with food. It 

 should be borne in mind that they must never 

 be disturbed while changing their skins. Care 

 must be taken constantly to watch the breeding 

 cages, that the insect may be secured as soon as 

 it appears, and before it has had time to injure 

 itself by attempting to escape. 



e 



