278 SALMONID^E. 



rivers Leet and Eden afforded the trout, is in my opinion 

 the principal cause of their superior size and excellence. 

 This food consists of small shells, cadis-bait, and clouds 

 of flies." 



These chameleon-like transformations are not, how- 

 ever, always so rapid as in the above cases: in many 

 waters the change is much more gradual. Sir Humphrey 

 Davy, for example, in his "Salmonia," mentions an 

 instance in which trout, from a lake in Scotland, remark- 

 able for their deep red flesh, being introduced into 

 another lake where the trout had only white flesh, retained 

 their peculiar redness for many years. They appear to 

 have all associated together in spawning in the burn which 

 fed the lake, those newly introduced being easily known 

 by their darker backs and brighter sides ; but by degrees, 

 from the influence of food and other causes, the change 

 gradually commenced, the young fry of the imported 

 variety were less red in flesh than the parent fish, but 

 not till about twenty years had elapsed was the variety 

 entirely lost. Similar variations and changes are inci- 

 dental to trout in every part of the world where they 

 are known, and those of Canada are no exception to 

 the rule. 



The spawning time, though varying a little between 

 the extremes of the two Provinces, is about September, 

 and the young fry make their appearance in the shallows 



