68 



PRECAUTION AGAINST ESCAPE. There will always be 

 a difficulty in so arranging ponds, screens, outlets and 

 inlets as to keep the young try in their proper pond. 

 The water is very apt to work holes around the screens, 

 or rather around the boxes containing the screens. The 

 young fry will make their way through a wonderfully 

 small hole 5 , no matter how long the distance may be. 

 They will also get through between the screen and the 

 socket, unless these are very well fitted together, and 

 wherever there is a crack into which they can get their 

 large heads., they will put them in so tightly that they 

 cannot extricate themselves, but will die. In short, 

 wherever ypu can run the big blade of a jack-knife, there 

 the young trout will go. In making a pond for them, it 

 is best to beat the edges with a spade until they are per- 

 fectly smooth, or, better yet, to put a board around the 

 edges to the depth of a foot. 



CLEANING SCREENS. If the screens are not kept well 

 cleaned, two consequences follow. First, the water runs 

 over the top of the screens instead of fnrough them, and 

 the young trout escape; and second, when the screens 

 are taken out to be cleaned a rush of water follows their 

 removal, carrying away with it numbers of trout into the 

 next pond. Whenever you are going to clean the screens 

 drive all the trout from their vicinity, then take the 

 screens out and wash them with a stiff brush/ They 

 may be first raked off with a rake if they are made of 

 slats, and then taken out and cleaned. They will re- 

 ; quire attention always once and sometimes twice a day. 



DISEASES. This'part of fish : raising is least understood as 

 yet. After the egg sac is absorbed and the fry begin to 

 swim about, a sick one is very easily distinguished. The 

 healthy trout swim in the current with their heads up 



