GROWING THE LARGE TROUT. 2O/ 



ference in the color of their meat is sometimes caused 

 by certain kinds of feed ; the fresh-water gammon or 

 polex being supposed especially favorable to the pro- 

 duction of red-meated trout. 



It is certainly true that their growth depends very 

 much upon the nature of their food. Francis, in his 

 Fish Culture, mentions the following experiment, of 

 which he says he once heard.* 



" Equal numbers of trout were confined for a certain 

 time by gratings to their several portions of the same 

 stream. The fish in one of the divisions were fed en- 

 tirely on flies, in another upon minnows, and in the 

 third upon worms. At the end of a certain period, 

 those which had been fed on flies were the heaviest 

 and in the best condition, those fed on minnows oc- 

 cupied the second place, while those fed on worms 

 were in much the worst order of the three." f 



The age to which trout live is not known. Seth 

 Green says that twelve years is probably about the 

 average age, and that they are in their prime between 

 the age of three years and ten years. I am inclined 

 to think that they live to a greater age than this. 

 Other kinds of fish in parks in the Old World are 

 known to have attained enormous ages,$ and to have 



* Francis on Fish Culture, p. 113. 



t The result of these experiments should be received cau- 

 tiously, as it is doubtful whether all the other modifying condi- 

 tions were so exactly alike that the results were wholly due to the 

 difference of food. For illustration, a considerable difference in 

 temperature, or in the quantity of food, would affect the condition 

 of the fish more than the difference in the nature of the food. 



\ Pike and carp in artificial ponds have been repeatedly found 



