143 



of the shad-batcbing operations were practically confined 

 to the waters in which they were practiced, and in those 

 waters were proportioned to the extent to which such 

 operations were carried. 



Experiments made with salmon in Europe clearly 

 established the proposition, as far as these fish were con- 

 cerned, that they always returned as mature fish, after 

 their sojourn in the ocean, to the rivers in which 

 they were hatched and from which they emigrated 

 when young. They were marked in various ways 

 usually by cutting off the adipose second dorsal fin 

 while in the smolt stage, when they were preparing to 

 descend to the sea ; and it was found that they invariably 

 returned to their breeding places, except in a few instan- 

 ces, which might safely be attributed to accident. Their 

 residence in the salt water being short, these experiments 

 were easily made, and as the fisheries were mainly in 

 private hands, and under close supervision, the results 

 could be obtained with accuracy. Another discovery was 

 made in the same connection by the deep-sea fishing, to 

 the effect that these same salmon did not roam over dis- 

 tant portions of the ocean, or even descend to great 

 depths, but remained near the mouths of the rivers to 

 which they belonged. 



Shad remain much longer in the ocean, requiring three 

 and four years to become mature, although the males 

 probably reappear a year earlier than the females ; but 

 there is every reason to believe that the same rule governs 

 their motions that applies to the migrations of the salmon. 

 It may, therefore, be concluded that shad do not roam 

 about the "vasty deep" in immense shoals, making jour- 

 neys of thousands of miles, and sending off relays to each 

 river whose mouth they pass, but that they remain quietly 

 near the streams where they are bred till the time comes 



