82 DOMESTICATED TROUT. 



2. In ponds the young fish are exposed to all their 

 enemies, whose name is Legion. Without enumerating 

 them all again, it is sufficient to say that birds, frogs, 

 and snakes will depopulate a pond of young trout with 

 surprising despatch. 



Rearing boxes being so prepared that when the lid 

 is shut down nothing can get in and nothing get out, 

 the safety of the fish is by this arrangement immeas- 

 urably increased. 



3. In ponds the green Conferva (frog-spittle) may 

 grow. If it does, it will probably cost you a great 

 many fish. It will not trouble you in the rearing box. 



4. The comparatively still water of ponds is often 

 unfavorable to the young fry inclined to be sickly. 

 This objection is obviated in the rearing box. 



5. In ponds there are likely to be unnoticed crevi- 

 ces, — at least, more than in rearing boxes, — where 

 the young fry often escape without your knowledge. 

 In rearing boxes perfect security can be obtained in 

 this respect. 



6. Dangers sometimes exist in ponds for weeks un- 

 noticed. In rearing boxes the trout and the whole 

 apparatus are so wholly under your eye that perfect 

 security from this source, also, may be acquired. 



7. When in ponds, you cannot keep account of the 

 numbers of the fish without much trouble. When in 

 rearing boxes, they can be taken out at a moment's 

 notice, and counted. 



Seth Green suggests that the hatching troughs be used 

 until the fish are large enough for ponds ; this, he says, 

 saves one removal. This may answer sometimes, but 

 it is open to these objections : — 



