52 THE NEW ART OF BREEDING FISH. 



fecundated with Salmon's milt, by the operations of 

 Messrs. Berthot and Detzem, on the Ehine, have 

 been sent to me, and have been hatched in my la- 

 boratory in Paris. Salmon's eggs fecundated by 

 trout's milt, have been hatched in like manner. 

 It now remains to be determined if the experiment 

 of crossing these two kinds will, in like manner, suc- 

 ceed with all others of the same family ; and, 

 also, whether other kinds belonging to a different 

 family, the pike, for example, mixed with the first, 

 can procreate together. 



The difficulty which the author of the memoir 

 published by the Count de Groldstein encountered 

 was, that the pike spawns in April, while the sal- 

 mon and trout spawn in November and December ; 

 but now, as we can procure the eggs or the milt of 

 the salmon of the Danube towards the end of April, 

 that obstacle to experiment is removed. We can 

 try the fecundation of eggs of this salmon with the 

 milt of the common ombre, and of eggs of the om- 

 bre with milt of salmon, and of eggs of both with 

 milt of the pike, etc. 



The Chinese produce these results with golden 

 carp, of which they procure infinite varieties ; but 

 their trade consists in confining together the varieties 

 of the same species, and allowing them to producB 

 cross breeds by natural propagation. 



