82 SALMONID.E. 



tlieir ova to tlie weedy shoals, where the vegetables, in process 

 of their growth, under the influence of the sun, distribute air 

 through the waters around them. 



"The science required for this object" — that is to say, the 

 raising foreign fishes for the stocking of home waters — thus 

 speaks Sir Humphrey Davy, in his delightful work, " Salmonia " 

 — " is easily attained, and the difficulties are quite imaginary. 

 The impregnation of the ova of fishes is performed out of the 

 body, and it is only necessary to pour the seminal fluid from the 

 milt upon the ova in water. Mr. Jacobi, a German gentleman, 

 who made, many years ago, experiments on the increase of 

 Trout and Salmon, informs us, that the ova and milt of mature 

 fish, recently dead, will produce living offspring. His plan of 

 raising Trout from the egg was a very simple one. He had a 

 box made with a small wire grating at one end in the cover, for 

 admitting water from a fresh source or stream, and at the other 

 end of the side of the box there were a number of holes, to 

 allow the exit of the water ; the bottom of the box was filled 

 with pebbles and gravel of different sizes, which were kept 

 covered with water that was always in motion. In November, 

 or the beginning of December, when the Trout were in full 

 maturity for spawning, and collected in the rivers for this pur- 

 pose, upon the beds of gravel, he caught the males and females 

 in a net, and by the pressure of his hands received the ova in a 

 basin of water, and suffered the milt, or seminal fluid, to pass 

 into the basin ; and after they had remained a few minutes 

 together, he introduced them upon the gravel in the box, which 

 was placed under a source of fresh, cool, and pure water. In a 

 few weeks the eggs burst, and the box was filled with an immense 



