90 FISH CULTUKE. 



the living deposited in the rearing tray. This is 

 the work of hut a few minutes, and perfectly clean 

 quarters can he afforded the newly-hatched fish — 

 a matter of no little importance to their health and 

 well-doing, for if cleanliness was needful in the egg 

 state, it is of vital necessity to the fish. Where 

 gravel is used for the ova this cannot he insured 

 without a great deal of lahour and trouhle ; either 

 the fish must he picked out as hest they can be — a 

 process involving the slaughter of many — or the dirt 

 must be picked out, and this latter is impossible. 

 The gravel wiU, in spite of all you can do, retain 

 some impurity. However this be accomplished, it 

 is a long, tedious, dirty, wasteful, and imperfect job ; 

 whereas the French is speedy and clean, and entails 

 no loss whatever. The same trays that the fish were 

 hatched in may, if it be wished, be used as rearing 

 trays, a very thin coating of gravel being put on the 

 bottom, and the number of fish hatched in each 

 tray reduced. The greatest cleanliness is necessary 

 during the period of alevinage. Even into the purest 

 water minute particles of matter will find their way 

 somehow, and in the earlier stages of the alevins' ex- 

 istence the skin is soft, and, according to Dr. Davy,i 



' " The Angler in the Lake District," au interesting and scientific 

 little wori, by Dr. John Davy, F.E.S. 



