TROUT BREEDING. 67 



they begin to move about, wire screens should also be 

 placed across every fourth or fifth nest, to confine them in 

 apartments, so that they may not be over-crowded in any 

 one part of the trough. The water should also be deep- 

 ened, by placing additional strips an inch wide on top of 

 those where the screens are placed; and an additional 

 supply, but not enough to wash them in numbers against 

 the screens, should be let on. If there are too many in 

 one apartment, a portion may be removed into another 

 where there are not so many, by lifting them out with the 

 little net already described. 



Some of the fry, as I have before remarked, will be 

 puny, and others large and vigorous dUb ova. The latter, 

 when two months or ten weeks old, will not hesitate in 

 their efforts to swallow those that are just hatched out, and 

 will generally succeed in doing so. Therefore, if a month 

 or two should elapse in planting the whole length of a 

 trough with eggs, it is necessary to protect the late from the 

 early comers. When the fry become lively, the bottom of 

 the trough can be cleansed by washing the gravel, com- 

 mencing above and stirring it in each successive nest 

 towards the lower end. The young fish will move out of 

 the way and resume their places as the water becomes 

 clear. 



Treatment of the Fry. — When the sac has nearly disap- 

 peared, a little food should be offered to the fry at intervals 

 of two or three days; when they begin to take it readily it 

 should be supplied to them twice every day. They will 



