TROUT 



should be kept upon the hatching trays as it 

 is marvellous how such creatures find their way 

 in, in spite of all precautions. Birds of several 

 kinds are also likely to cause great damage un- 

 less the ova and young fish are carefully guarded 

 from their depredations. 



In a short time, probably within a few days 

 of receiving the ova, the amateur will find that 

 the young fish are beginning to hatch out. 

 They generally come out tail first, and in wrig- 

 gling this about in their attempts to get further 

 out, they propel the ovum about the bottom of 

 the tray. When the little fish attempts to come 

 out head first, he sometimes gets into difficulties 

 and if this is observed, he may be helped by a 

 gentle touch with a feather or a camel's hair 

 brush. 



When first hatched out the young fish have 

 a large translucent protuberance on the under- 

 surface. This is the umbilical or yolk-sac, and 

 contains the nourishment upon which the little 

 fish lives during the first stage of its life after 

 it is hatched. This sac is gradually absorbed 

 but until it is absorbed the young fish are called 

 " alevins." At first the little fish do not require 

 any food, but they generally begin to feed in 



39 



