108 AMERICAN FISH CULTURE. 



required. The short time which, under favorable circum- 

 stances, would be requisite in artificial incubation in New 

 England and in the Middle States, where the salmon could 

 be naturalized, would produce the fry in winter, and give 

 them such a start that nearly all would probably reach the 

 smolt state and go to sea the second summer. 



In my remarks in the " American Anglers' Book," on 

 the time required to hatch out salmon ova in Canadian 

 rivers, I have alluded to the fact that many of them, where 

 the water is shallow enough, and where it affords the 

 requisites for a spawning-bed, freezes to the bottom; and 

 have inferred from this that the eggs do not (at least not 

 all of them) lose their vitality. In proof of this theory, it 

 is stated in the London " Fisherman's Magazine" that sal- 

 mon ova had been kept in ice ninety days, and that half 

 of these frozen eggs were afterwards hatched out. 



When the young salmon frees itself from the shell, it is 

 about three-fourths of an inch long, and has the same um- 

 bilical sac which we observe in the fry of brook trout. 

 This it carries for about six weeks; during this time it 

 refuses all food. As soon, however, as this sac is absorbed, 

 its predacious instinct is observed, rising eagerly at the 

 smallest insect or atom, and seizing animalculse beneath the 

 surface. In pisciculture the food of the fry is much the 

 same as those of the trout ; I therefore refer the reader 

 to the directions for feeding the young of that fish. 



Although the incubation of salmon ova is similar to that 

 of the trout in breeding them artificially, the manipulation . 

 of the fish is different on account of the large size and vigor 



