TROUT BREEDING. 31 



It requires careful forethought, that the size of the ponds 

 may be in accordance with the supply and temperature of 

 the water. The cause of failure in most cases has been 

 where persons have attempted to supply large ponds with 

 a diminutive stream ; thus exposing a large area to the heat 

 of a summer atmosphere and the rays of the sun. The 

 shape also of the ponds has much to do with the tempera- 

 ture of the water ; an oblong is preferable to a circle ; if 

 the width of the pond is one-tenth of its length, so much 

 the better, as the water passes through quicker, and retains 

 its coldness to a greater degree. Trees, though they may 

 shade and serve to beautify, cause much annoyance, as the 

 leaves falling or being blown into the water, sink and accu- 

 mulate on the bottom, or are carried by the current against 

 and clog the wire screens which are placed in the outlets 

 to keep the fish in the ponds allotted to them. A cheap 

 and efficient method of diminishing the surface exposed to 

 the sun is with floats or platforms made of rough boards, 

 moored in the ponds ; these also make an acceptable shade 

 and hiding-place for the fish. 



The race-ways, which, as I have before remarked, are 

 the spawning grounds of the fish, should be five or six 

 inches deep, from two to three and a half feet wide, and 

 from twenty to sixty feet long, according to the size of the 

 ponds and the supply of water. The bottoms of the race- 

 ways should be covered to the depth of three inches or 

 more with fine gravel for the trout to make their ne.sts in. 

 The sides should be of boards an inch thick and twelve 

 inches wide. If tin slope of the ground is such that there 



