14 PRACTICAL TROUT CULTURE. 



season. As soon as the spawn was deposited, the 

 parents were removed and the eggs protected from 

 the attacks of enemies. This process is still prac- 

 ticed with success in various portions of the Con- 

 tinent. In 1752, Spallanzani, the eminent Italian 

 naturalist, performed for the first time the opera- 

 tion of artificial impregnation, not with fishes, but 

 with the frog ; yet the fact was established, and 

 it was not long ere practical benefit was derived 

 from it. To Lieut, (afterward Major) Gr. L. Ja- 

 cobi, of Hollenhausen, must be given the credit 

 of first introducing, if not discovering, the pro- 

 cess of artificial impregnation of the eggs of fishes. 

 The results of his experiments, which were pre- 

 eminently successful, were published in 1763 in 

 the Hanover Magazine, a local periodical with 

 but a small circulation, and for a few years ex- 

 cited no attention ; but by its translation into 

 Latin by Goldstein, and French by Duhamel du 

 Monceau, in 1773 it was brought to the notice of 

 the scientific world. Jacobi's account of his 

 method forcibly recalls to mind the pictures of a 

 poor, tortured salmon being held up by a hand 

 to which no body is attached, her eggs falling in a 

 graceful curve into a pan of water beneath, which 

 were wont to ornament the covers of the numerous 

 French pamphlets on pisciculture. Jacobi says : 

 " Place in a clean vessel about a pint of pure 



