44 AMERICAN FISH CULTURE. 



nests or apartments from sixteen to eighteen inches long, 

 by placing strips across; over these strips the water 

 flows in a slight ripple, and the force of the current is 

 thereby broken. The bottom of the trough is covered 

 with clean gravel, to the depth of an inch or so, to receive 

 the eggs, over which the water, an inch deep, flows in a 

 gentle current. This plan has generally been discarded in 

 France, but here, by using pure spring water after passing 

 it through three or four flannel screens and a small heap 

 of fine gravel, it is perhaps as efficacious as the French 

 mode. Our largest fish culturist, Seth Green, has by these 

 simple means hatched out ninety per cent., and Stephen 

 H. Ainsworth as high as ninety-eight per cent, of the ova. 

 In my first experiment, which was with filtered Schuylkill 

 water, a thousand eggs produced nearly seven hundred fish. 

 A floating box for hatching is also used. It is made of 

 boards generally a half inch thick ; the bottom is covered 

 with fine wire gauze, which should be painted ; on this the 

 eggs are distributed. If the box does not set deep enough 

 to allow the water to cover the eggs an inch or an inch and 

 a half, sufficient weight should be placed on the cover to 

 sink it to that depth. If the bottom of the box is made of 

 boards and gravel strewed over it, two or three rows of 

 large gimlet holes should be bored in each end below the 

 water line. These boxes are usually two feet long, eighteen 

 inches wide, and about six inches deep, and are tied to a 

 strip extending across the raceway and allowed to float in 

 the current. A box of this kind can also be placed in a 

 spring, its size corresponding with the area. By this mode 



