226 THE PERCH 



being too deeply buried in the gravel or for other 

 reasons. The few fry which ultimately come into 

 existence from a batch of trout eggs are attacked by 

 all kinds of enemies, such as eels and other voracious 

 fish, water birds and water insects, and very probably 

 not a few die from want of food. Though trout of 

 any size yield about a thousand eggs to each pound 

 of their weight, not more than two or three of the 

 fry proceeding from one redd attain maturity. This 

 must be the case, for if trout were even to double in 

 numbers every year the rivers would soon contain 

 more fish than water. 



So much for Nature. Science succeeds far better. 

 Practically all the eggs which the trout culturist 

 handles are properly impregnated, and very nearly 

 all hatch out. In the fry stage there are, as a rule, 

 heavy losses ; but under favourable conditions the 

 ultimate result is from forty to fifty mature trout for 

 every hundred eggs which have been hatched. Trout 

 and salmon culture is one of the triumphs of science. 

 I mention these facts to make an interesting com- 

 parison. 



In perch culture, on the other hand, it has been 

 found better to leave a very great deal to Nature, 

 rendering assistance here and there in the way of 

 affording suitable support on which the eggs may be 



