121 



being made of proper width, it fills, and the coarse 

 screen is laid over it, with the wire side down. 

 There is a space, between the two screens, of one inch, 

 protected from invasion on the top and bottom by the 

 wire screens, and on all the sides by the inch strip of the 

 small screen. The top screen, which has sides three or 

 four inches deep, is then to be filled with coarse gravel, 

 BO coarse that it will not pass through the meshes, to the 

 depth ot two inches. This gravel will overcome the 

 buoyancy of the wooden frames, and cause them to sink 

 in the water. Now the screens are ready for use. 



A trout comes along, and finds the gravel. She sees 

 no screens — only some nice gravel for nest-building, in 

 what appears to be a shallow box. Suspecting no evil, 

 she proceeds to make her nest, and in the process of 

 " slirting out " gravel with her tail, she moves it away 

 from the meshes of the coarse screen, and leaves the bot- 

 tom of her nest an open network. On this she emits 

 her eggs, which are at the same time fecundated by the 

 emission of the milt of the male trout lying by her side. 

 The eggs fall down into the nest, but pass through the 

 coarse wire screen, and are caught by the fine meshes of 

 the lower screen. There they are safe. The trout cov- 

 ers up the hole as usual. The hangers-on find no eggs 

 to devour, and go their way. Another trout may make 

 her nest in the same place, without disturbing the eggs 

 already laid, safe in their resting-place. Here they may 

 be left to hatch, or you may take a pan of water, and 

 taking off the upper screen, gradually lift up the lower 

 screen, brushing the eggs to one corner with a feather, 

 and tip them all at last into your pan without having ex- 

 posed a single egg to the atmosphere, without any trou- 

 ble in handling the fish, and without any loss of the 

 breeders. 



