THE TROUT 5 



which it derives nourishment. Gradually, 

 however, the sac disappears, and the little 

 fish is able to swim and go in search of food 

 such as water -fleas, etc. Thus, as they gain 

 strength, the alevins are capable of turning 

 the tables on their smaller enemies, and 

 " get a bit of their own back '' from the 

 larvae and caddis-worms. With the return 

 of the adult spawning trout in autumn, the 

 alevins (or fry) succeed in devouring a certain 

 number of the eggs. They are, however, 

 still obliged to keep an eye open for their 

 enemies, which now include the spawning 

 fish ; as well as eels, kingfishers and the like. 

 By the following spring, those alevins which 

 survive are known as yearlings, and they then 

 begin to drop down into deeper water. By 

 the time he is a two-year-old, the trout may 

 be from six to twelve inches in length ; and 

 in their third year the females join the throng 

 en route to the spawning grounds, where 

 they deposit their eggs. With luck a trout 

 may reach old age, but if he does he becomes 

 hook- jawed and lanky ; and he loses all 

 the brilliant colouring of his younger days. 



3. Vision, hearing and smell. 

 In addition to being endowed with remark- 

 able activity, trout in power of vision are 



