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then a supply of water filling a pipe five inelieS square 

 (making twenty-five square inches) for the size of ponds 

 shown in plate on a previous page calculated to sustain 

 five thousand fish in the second, and two thousand fish in 

 the third ponds. The first pond to receive six or eight 

 thousand young fish, need not have more than two or 

 three square inches of the water. This estimate of num- 

 ber of fish is purposely made low. More fish may be 

 able to live with the supply mentioned ; but the number 

 given certmnhj can. 



Growth of Tbout. — It is impossible to tell the age of 

 a trout by its size, as its size depends very much upon the 

 quantity of food which it obtains. It is a general rule 

 that with good feeding a trout three years old will weigh 

 one pound. They have been known to live for years at 

 the bottom of a well, where the supply of food must have 

 been extremeKy limited, and remain through all those 

 years, apparently at the same size. Then again, with good 

 feeding, they will more than double their weight in a sin- 

 gle season. Trout will not grow so fast in swift running 

 water as in a pond The largest trout are never caught in 

 narrow parts of the stream where the water runs fast. 

 But where the stream swells out into a dark and still pool, 

 there the patriarchs are found. We presume that the 

 largest trout now taken in this country are found in the 

 lakes of Maine. Some will grow much faster than others 

 under any circumstances. A few will always look lean 

 and hungry no matter how much they are fed, and others 

 seem to have a peculiar knack of getting fat. Still the 

 rule of good feeding applies equally to all. They will not 

 grow so fast when three or four years old as before ; that 

 is, the rate of increase diminishes with age. The average 

 age of trout is perhaps twelve or fourteen years. On 

 this point we cannot speak with certainty. We have 



