TROUT BREEDING. 43 



of the grille are near enough together to hold the eggs ; 

 while any floating dirt falls hetween to the bottom of the 

 tray, and can be removed by drawing the water off through 

 a hole which is kept corked at one end in the bottom. 

 The young fish, as they are hatched out, also drop between 

 the bars, and are removed through the same aperture and 

 place^d in other troughs or apartments. These trays can 

 even be scrubbed and replaced, by moving the grille (which 

 may safely be done after the young fish are developed in 

 the ova), to a spare tray kept for the purpose. The trays 

 are placed in shallow vessels or cisterns, elevated to the 

 height of a man's waist; each cistern, which is thirty or 

 forty feet long, containing a proportionate number of trays. 

 It is not deemed advisable, however, that a jet of water 

 from the supply pipes should flow through more than six 

 trays. 



Another mode in France, is to have a series of troughs 

 arranged like steps, one slightly above the other, as shown 

 in illustration at end of next chapter. The water pour- 

 ing through a hole in a little jet at one end of the 

 upper trough, and running the length of that below, 

 discharges in the same way, and runs the length of the 

 next trough. This plan has the advantage of aerating the 

 water as it enters each, and can be placed in any spare 

 room of proper temperature in one's dwelling. 



In this country a much more simple, though not as effec- 

 tual, mode of getting rid of sediment and suppressing the 

 growth of byssus is pursued. A 'wooden trough, twelve or 

 fifteen inches wide, and four inches deep, is divided into 



