REARING THE YOUNG FRY. I93 



firms the theory just advocated, that the causes of 

 death can be removed. 



This has been a long digression, I know. I beg 

 the reader to excuse it. I was saying that if you 

 took good care of the young fish, hatched and pro- 

 vided for them as has been suggested, there were 

 ninety chances out of a hundred that you would raise 

 them. This remaining contingency, however, of tak- 

 ing good care of them, is no trifle. It involves constant 

 vigilance and a very faithful attention to all the con- 

 ditions upon which the life and growth of the young 

 trout depend. 



As any further directions as to the care of them 

 would be a repetition of what has already been written, 

 I will merely advise the beginner to be always on his 

 guard against accidents and dangers ; to visit the fish 

 the first thing in the morning, and the last thing at 

 night ; to carry out Macbeth's resolution, " to make as- 

 surance double sure,'' even if it seems like taking a 

 "bond of" certainty. And now, hoping that the reader 

 will have the best of luck during this delicate period of 

 the trout's career, let us pass on to the consideration 

 of the unpleasant but important subject of the diseases 

 of young trout. 



Section III. — Diseases of Trout Fry. 



We are now come to the department of trout cul- 

 ture which is the least known, namely, the diseases to 

 which young trout are subject. This is an almost un- 

 trodden field of study,* where little is known, and 



* The art of raising horses and other domestic animals has 



