i8o Bass, Pike, and Percb 



the small streams on the spring rise, plough 

 up the spawning beds, smothering the eggs and 

 killing the helpless fry. As brook-trout spawn 

 in the fall they escape this calamity, the fry 

 being old enough in April to take pretty good 

 care of themselves. The decrease of both trout 

 and grayling is commonly attributed to over- 

 fishing; but while this may have its influence 

 to a limited extent in lessening the numbers for 

 a season, other causes must be looked for to 

 account for the permanent depletion of certain 

 waters. 



A stream or pond will support but a 

 limited number of fish, the number depending 

 on the supply of natural food for both young 

 and mature. By the supply of food on one 

 hand, and the natural enemies of the fish on 

 the other, a certain balance is maintained which 

 if disturbed by, say, overfishing one season, 

 will be restored by natural laws the next. And 

 this state of affairs will continue so long as the 

 natural conditions of the waters remain un- 

 disturbed. 



By cutting down the pine trees at the sources 

 of the streams and along the small tributaries, 

 which are the spawning grounds of both trout 



