AMBEICAN OHAEES (B E O O K-T E O UT) 



spawn from October to April, more or less, during which period 

 they are protected by law. The hatching period depends upon 

 the temperature. Mr. Ainsworth's experiments showed that if 

 the water temperature was thirty-seven degrees the eggs would 

 hatch in one hundred and sixty-five days ; one hundred and three 

 at forty-one degrees ; eighty-one days at forty-four degrees ; 

 forty-seven days at fifty degrees ; and thirty-two days at fifty- 

 four degrees. Seth Green found that if the temperature was 

 fifty degrees, the eggs would hatch in fifty days, each degree, 

 warmer or colder, making five days either way. When the young 

 appear they are attached to the yolk from thirty to eighty days, 

 and from now on they increase in a ratio to the food supply- 

 Thus in two years a well nurtured fish wiU weigh a pound ; a 

 poorly nurtured fish from the same brood half an ounce. 

 Ainsworth observations showed that yearlings weighed two 

 ounces ; two year old fish a quarter of a pound ; three year old 

 fish a half pound ; four year old fish a pound. This for domestic 

 fish. 



In the wild state under the most favourable conditions the 

 increase is much greater. A Eangeley Lake charr, which was 

 tagged by Mr. George S. Page in 1871, gained two pounds in 

 two years. Charrs are mature in from one to two years. The 

 nesting habits of the brook-trout are most interesting, and are 

 well described by Mr. James W. Miles as follows : 



' His whole wooing is the most polite attention and the gentlest of 

 persuasions. He moves continually to and fro before his mate parading 

 his bright colours, while she rests quietly, with her head up stream, vibra- 

 ting her fins just sufl&ciently to keep her from floating down. At Water- 

 viUe, Wisconsin, I had the opportunity of watching their habits. A pair 

 of large trout had selected a spot near the bank of the stream, where 

 the water was about ten inches deep. The female had fanned the 

 gravel with her tail and anal fin until it was clean and white, and had 

 succeeded in excavating a cavity. They were frightened away as I came 

 to the edge of the bank. Concealing myself behind a willow bush, I 

 watched their movements. The male returned first, reconnoitering the 

 vicinity, and, satisf jdng himself that the coast was clear, spent a half 

 hour in endeavouring to coax the female to enter the nest. She resting, 



323 



