46 ' REPORT ON ARTIFICIAL FISH-CULTURE. 



they are transparent and yellow — so fecundated 

 they become whitish or rather opaline. A trout, 

 aged some two years, and weighing about 125 

 grammes, can furnish about 600 eggs ; a trout 

 of three years, 700 to 800; and it is also to be 

 noticed that the milt of one male is enough to 

 fecundate the eggs of half a dozen females, or 

 even more. 



Messrs. Gehin and Remy placed the eggs so 

 fecundated in a tin box pierced with holes on a 

 gravel bed: these boxes are about fifteen centi- 

 metres in diameter, and eight deep, and can 

 contain each a thousand eggs. 



They are then to be placed in some stream- 

 let of which the waters are pure and lively 

 but not deep: in this they are partially buried, 

 and so disposed that the water in the boxes is 

 rapidly renewed, for the agitation of it is neces- 

 sary to insure the respiration of the embryos, 

 and also to hinder the development of confer- 

 vas, which will not be slow to catch and destroy 

 the eggs if the water be stagnant., The develop- 

 ment of these embryos lasts four months, and it 

 is generally towards the end of March or in April 

 that the hatching takes place ; during six weeks 

 more the new-born trout carry under the abdo- 

 men the umbilical vesicle which holds the re- 

 mains of the nutritive matter, analagous to the 



