328 THE AXGLEE-NATUEALIST. 



years. The situation chosen for, and the mode of con- 

 ducting the spawning-process are very similar to those 

 noticed in the Salmon (p. 361), — the eye, however, of the 

 young fish becoming visible in about three weeks, and the 

 egg being usually hatched in from forty to fifty days. The 

 number of eggs, in proportion to the weight of the fish, 

 is about the same as in the case of the Salmon. The 

 yolk-bag is absorbed in from three to five weeks ; and in 

 six weeks or two months the young fry are about an inch 

 long and able to shift for themselves. From this time 

 their growth is rapid or slow according to the nature and 

 quantity of their food and other local circumstances. 



In order to ascertain the relative nourishment of the 

 different descriptions of food, some interesting experiments 

 were made not many years ago. Trout were placed in 

 three separate tanks, one of which was supplied daily with 

 worms, another with live minnows, and the third with flies. 

 The result was, that the fish fed with worms grew slowly 

 and had a lean appearance, — those dieted on minnows 

 became much larger, — whilst such as were fattened upon 

 flies only, attained in a short space of time extraordinary 

 dimensions, weighing twice as much as both the others 

 put together — the quantity of food eaten by them being 

 actually less *. 



On another occasion Trout were kept for many years in 

 a store stream, and tested with various kinds of diet, when 

 it was ascertained that in some instances the increase in 

 * Stoddart, Art of Angling in Scotland. 



