84 DOMESTICATED TROUT. 



one end, and some gravel on the bottom, with a stream 

 of water running through, is a rearing box, and will 

 do, if only a hundred or two young fry are to be 

 raised. 



A rearing box in its most perfect form is a more 

 elaborate and complicated thing, and should combine 

 these points,* viz. : — 



i. A fall of water. 



2. A current of water. 



3. Protection against too forcible suction through 

 the outlet screen. 



4. Security from overflow. 



5. Absence of fixed hiding-places. 



6. Compactness of fish themselves for feeding. 



7. Protection against outside enemies. 



8. Perfectly tight joints. 



9. Protection against fungus. 



1. A fall of water. The very young fry need all 

 the vitality and freshness which can be given to the 

 water ; and that imparted to it by a fall immediately 

 above them is too valuable to be disregarded. Ex- 

 perience has proved, also, that all trout do best just 

 below a fall of water. 



2. A current. If you want to make hardy fish, give 

 the young fry a current to head up against ; this is not 

 only more natural, but it will keep them clean and 

 vigorous, while in (relatively) still water they will often 

 take on a fungus growth or fin disease, which will 



* It should be added here, that ponds for young fry should, as 

 far as possible, be constructed on the same general principles that 

 are recommended for rearing boxes. 



