FISHERIES 



287 



in which adult fishes are confined. In a hatchery for such fishes 

 the eggs are placed in various receptacles, where they are kept 

 aerated by suitable devices. Mac Donald's hat-ching-bottle (fig. 

 1209) is largely employed in the United States for the small eggs 

 of shad and other fishes, of which one bottle will accommodate 

 about 70,000. 



An important hatchery for cod has for some years been in 

 operation at Flodevig, near Arendal, in Norway, under the 

 superintendence of Captain Dannevig. In Scotland there is an 

 important hatchery, chiefly 

 used for plaice, connected with 

 the marine station at Nigg, 

 near Aberdeen, and there is 

 also one at Piel, on the coast 

 of Lancashire. There are, of 

 course, important hatcheries 

 for marine fishes in America. 



Regarding the value of 

 hatcheries for freshwater forms, 

 and fishes which, like the 

 salmon, spawn in rivers, there 

 can be no doubt. As to marine 

 fish -hatcheries, which aim at 

 maintaining or even increasing 

 the supply by liberating great 

 numbers of fry in the sea, the 

 data are at present too incomplete to estimate their utility. It 

 appears to be certain in some cases that good has been done by 

 them, one instance of the sort being afforded by the Norwegian 

 hatchery near Flodevig, but the expense involved is considerable, 

 and for some species and some localities may well turn out to be 

 so great as not to be justifiable. The large majority of the just- 

 hatched fry which are now from time to time placed in the sea are 

 destined to perish before growing to a marketable size, and it may 

 in the end turn out to be necessary to carry the culture to a stage 

 which will give a greatly increased chance of survival. But this 

 is notoriously difficult, and a large amount of experiment is 

 necessary before success is likely to be attained. And even in 

 the event of the various obstacles being surmounted, the greatly 

 increased expense of such a method may prevent its adoption. 



e one on 



MacDonald's Hatching Bottle 

 the left is arranged for hatching purposes, and the other 

 contains fry. Course of water indicated by arrows. 



