140 TROUT 



adapted to cope with turbulent waters, such 



as the fresh-run salmon loves and stems with 



ease. 



A peculiarity of the genus trout is that, 

 relatively, the fish vary enormously in size, 

 more so perhaps than any known species. 



But this is wholly a question of food supply ; 

 where the waters flow rapidly over a rocky 

 bed, and no weed exists, fish food is scarce, 

 and in consequence the trout, though reaching 

 maturity, rarely exceed a few inches in length. 

 Lower down the river, where the streams are 

 quieter and aquatic weed abounds, the aver- 

 age size is much larger, including fish from 

 I lb. and upwards ; in short, the richer and 

 more abundant the food the larger the trout. 

 When trout get to be of a certain age they are 

 wont to neglect the usual diet of flies, worms, 

 caddis, etc., for fish of all kinds, not excepting 

 their own species. In these cases they grow 

 to a great size, sometimes equalling the pro- 

 portions of salmon. This being so, we can 

 believe that trout having once got into the sea, 

 where the right kind of food (fish fry) is abund- 

 ant and procurable at a minimum of physical 

 exertion, must quickly fatten up, and also 

 that the effect of salt water would soon change 

 the appearance of the fish. Now, a river that 

 contains salmon invariably holds trout, and 



