92 THE NEW AET OF BREEDING FISH. 



the milt can be usefully employed in a state of im- 

 maturity, and the life of the parent fishes would be 

 endangered by rough handling. 



On coming in contact with the spermatised wa- 

 ter, the eggs change color : before fecundation they 

 are transparent and yellow : so fecundated they be- 

 come 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 noted that the milt of 

 one male is enough to fecundate the eggs of a half-a- 

 dozen females or even more. Messrs. Gehin and 

 Eemy placed the eggs so fecundated in a tin box 

 pierced with holes on a gravel-bed : these boxes are 

 about fifteen centimetres in diameter, and eight 

 deep, and can contain each a thousand eggs. They 

 are then to be placed in some streamlet 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 agita- 

 tion of it is necessary to assure the respiration of 

 the embryos, and also to hinder the development of 

 confervas, which will not be slow to catch and de- 

 stroy the eggs if the water be stagnant. The de- 

 velopment 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 abdomen 



* Experience showB that the trout does not become nubile or 

 fit for propagation before the age of three years. 



