150 THE NEW AET OF BREEDING FISH. 



ducting the experiment of artificial impregnation, it 

 appeared to me to be very desirable that the male 

 should be taken with the female of his own selection 

 at the very moment when they were mutually en- 

 gaged in the continuance of their species. To take 

 a female from one part of the stream and a male 

 from another might not have given the same chance 

 of a successful issue to the experiment. Having 

 drawn the fish ashore, I placed the female, while still 

 alive, in the trench, and pressed from her body a 

 quantity of ova. I then placed the male in the 

 same situation, pressing from his body a quantity of 

 milt, which, passing down the stream, thoroughly 

 impregnated the ova. I then transferred the spawn 

 to the basin, slnd deposited it in a stream connected 

 with a pond previously formed for its reception, 

 which, however, I have not considered it necessary 

 to represent in the accompanying plan. The tem- 

 perature of this stream was 39 degrees ; of the river 

 from which the salmon were taken, 33 degrees ; and 

 of the atmosphere 36 degrees. The skins of the 

 parent salmon are now in my possession. On ex- 

 amining the ova on the 23d of February (50 days 

 after impregnation), I found the embryo fish dis- 

 tinctly visible to the naked eye, and even exhibiting 

 some symptoms of vitality by moving feebly in the 

 egg. The temperature of the stream was at this 

 time 36 degrees, and of the atmosphere 38 degrees. 

 On the 28th of April (114 days after impregnation), 

 I found the young salmon excluded from the egg, 



