826 EEPORT OF COMMISSIONKR OF FISH AND FISHERIES. 



through the thin net-like web which covered them, and at once it was 

 evident, to my great dehght, that they were in splendid preservation, 

 and far advanced in hatching, the eyes of the young fish being clearly 

 visible. With little loss of time the ova were transferred to the gravel 

 of the hatching-boxes, which had been prepared with great care, by be- 

 ing screened to insure a uniform size, and by boiling to destroy insect 

 germs which might be injurious to the ova. All were got into the 

 hatching-boxes the same evening, except one layer of about 7,000, 

 which were left under the ice till next morning. About G per cent, of 

 dead eggs were taken out at once, but many were adhering in clusters, 

 most of which I knew could not live, but which looked healthy enough 

 at the time. 



The next morning over 100 young salmon were hatched, and they 

 were lively little fellows even at that early stage of their existence. 

 When touched with a feather they would start off and swim round in a 

 cu'cle, and settle down again amongst the gravel. On the remainder of 

 the ova being transferred to the hatching-boxes several of the young 

 fish were found to have hatched out during the night, and during the . 

 day 400 or 500 made their appearance. 



Tlie ovum of the American salmon is larger than that of the British 

 species. It measures almost exactly a quarter of an inch in diameter. 

 It is of a transparent pink color, and is nearly globular, being slightly 

 elongated. The young fish is about an inch long, and it has attached to 

 it the umbilical sac containing the yolk of the egg, which is a clean 

 transparent red color, and seems quite as large as the egg from which 

 it has emerged. This sac contains the food of the young salmon for 

 three or four weeks, and is gradually absorbed, becoming smaller as the 

 young fish grows. 



The hatching process is effected simply by placing the ova on a layer 

 of gravel, over Avhich a stream of water is allowed to run. The temper- 

 ature of the water is a most important point, and I selected a spring 

 from its being of a uniform degree of cold and from its freedom from 

 sediment, which by settling on the egg interferes with the supply of 

 oxygen necessary for its vivification. As the supply from the spring is 

 limited, being only four or five pints per minute, I had a pipe laid down 

 from the creek supi^lying two filters which are used to increase the sup- 

 ply. The water from the pipe can be shut off entirely when its tem- 

 perature is too high,' but for so far the difference has not been great be- 

 tween the water from it and that of the spring. The permanent tem- 

 perature of the spring is 55° and the pipe supply has risen on hot days 

 to 02°, but the young fish did not seem to suffer in the slightest, and 

 those in the warmest water are further advanced. The hatching went 

 on favorably, but a large number of the eggs arrived at a certain stage 

 and failed to produce live fish. Sometimes after a struggle the head 

 would appear, and the little creature would ijerish in the effort to emerge 

 from the shell. In others, after the eyes were plainly visible, the living 



