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CHAPTER X. 



GENERAL REMARKS ON TROUT 

 BREEDING. 



There are other methods of hatching the eggs which 

 are partly natural and partly artificial, and which per- 

 sons can use who are not in condition to oversee the 

 eggs during their long period of incubation. Frames of 

 wood have been built over a raceway made from springs, 

 and on them gravel has been placed. The strips or 

 slats of the frame were wide enough apart for the eggs 

 to fall through into the lower part of the raceway, which 

 was closed at the lower end so as to force the water up 

 among the gravel. The frame was set at such a depth 

 as to give a couple of inches over the gravel, and 

 more or less under the frame. The fish were allowed to 

 spawn by themselves, covers being laid on to protect 

 them from disturbance. The eggs fell through the slats 

 as they were impregnated, and hatched below where 

 nothing could get at them. This yields a moderate per- 

 centage, and will work better than if the gravel is laid 

 on six inches thick, so deep that the eggs are retained in 

 it and cannot fall through. 



Another plan was to place a double set of trays or 

 screens, the lower one of such fine wire that the eggs 

 will not pass through ; that is, of about ten or fourteen 

 threads to the inch. This wire is attached to a frame, 

 made of inch stuff, and another inch strip nailed above it. 

 The upper frame is ot the same width and length, but the 

 sides are from three to four inches deep ; upon this a 

 coarse screen, of three or four wires to the inch, is 

 fastened. The fine screen is first laid in the race, which 



