58 AMERICAN FISH CULTURE. 



at the close of the spawning-season, and prevent the fry 

 that may be hatched out from coming down into the ponds. 

 This can be done by putting in a fine wire screen at the 

 lower end of the trap, and a coarse one to catch the leaves 

 and drift at the upper end. The race will thus be turned 

 into an out-door nursery, and the young fish can be taken 

 at the trap and turned into the first pond, when those from 

 Wie nursery under roof are transferred. 



Packing and transporting ova. As soon as the first for- 

 mation of the young fish can be seen, eggs may be sent off, 

 although some persons think that the eyes should be plainly 

 visible before transportation. The plan now pursued at 

 Huningue, is to pack them in short wide-mouthed glass 

 jars. In this country shallow tin boxes are generally used. 

 Both here and in France they are packed in damp moss, 

 the top and bottom of the jar or box being perforated so 



as to admit some air. The bottom of the box is covered 





 with moss, well washed and water pressed out, but still quite 



moist ; on this the eggs are spread so as not to overlie each 

 other. A layer of moss an inch thick is then placed on the 

 eggs. Then comes another layer of eggs, and so on until 

 three or four alternate layers fill the box. The tin boxes are 

 securely closed and packed with saw-dust between, in a 

 wooden box, a layer of saw-dust two or three inches thick 

 protecting the top, bottom, and sides, from exposure to 

 extremes of heat or cold. A tin box six inches in diameter 

 and three inches deep will, with the moss, contain easily 

 three thousand eggs. At a temperature from five to 

 fifteen degrees above freezing point, a box of ova, if care- 



