34 PISH CULTURE. 



thing over eighteen months old, the water in it should not 

 be more than six inches deep at the upper, and two feet 

 deep at the lower end. Young trout delight in shallow 

 water, and will therefore be found mostly where the race- 

 way enters ; as they grow larger they will seek the deeper 

 water at the lower end of the pond. The bottom of this 

 pond should be covered to the depth of two or three inches 

 with coarse gravel. 



Pond No. 2. — The fish, when they are old enough to 

 enter this pond, will require deeper water and more room. 

 It may therefore be a third or a half longer, two or three 

 feet wider, and have an average depth of three feet ; thus 

 containing four or five times as many cubic feet of water as 

 pond No. 1. The depth may be more uniform-; care being 

 taken to have a good depth and no gravel where the race 

 enters, so as to ofi'er no inducement for the fish to spawn 

 in the pond. The trout, spawning for the first time a few 

 months after entering this pond, and being still small, and 

 giving not over three hundred eggs to each spawner, it is 

 not requisite that the raceway supplying it should" be as 

 long or as wide as that leading into the next pond below. 



Pond No. 3 should contain double or three times the 

 number of cubic feet of water of the preceding, and have 

 an average depth of five feet. This, as well as the other 

 ponds, if it can be so arranged, should have a flume in the 

 bottom, so that it can be entirely drained if sufficient mud 

 should accumulate to make it desirable. The fish entering 

 this pond when somewhat over two and a half years old 

 will give double or thrice as many ova as they did the pre- 



