INTRODUCTION. 15 



water, though injurious to eggs, is wholesome and 

 beneficial to the fully formed fish of all ages. 



It is always a good precaution, where a stream is used 

 which has no trout in it naturally, to put in a few and 

 keep them there the year round, and see how it suits 

 them, before adopting it fully as a trout-breeding water. 



There is some conflict of opinion about the compar- 

 ative value of spring and brook water for raising trout. 

 As a rule, I think generally, all things considered, that 

 spring-water is best for hatching, and brook-water is 

 the best for raising trout. It is said that brook-water 

 is more natural for hatching ; that it hatches the trout 

 out at a better time, namely, in the spring, and that 

 the young fry, when they do come out, are uncommonly 

 lively. It is not certain, however, that brook-water is 

 more natural than spring-water for hatching, for in many 

 brooks, and in most of those with which I am acquaint- 

 ed, half the fish lay their eggs in spring-holes, or so near 

 the spring-sources of the stream that it is practically 

 spring-water that they are hatched in. Then, again, it 

 is a doubtful advantage, if any, to have them hatch late ; 

 and lastly, they are not sure, by any means, to make 

 better trout for being unusually lively in the earlier 

 days of their infancy. 



On the other hand, spring-water possesses, for hatch- 

 ing, the vast advantage over brook-water of being safer. 



I think that in hatching, except in very rare instan- 

 ces, brook-water can have no advantages which can 

 begin to offset this great counterbalancing advantage 

 of safety. You cannot be too sure of the water which 

 flows over your eggs. In most brooks you cannot be 



