INDUSTRIAL PROGRESS DURING THE YEAR 1872. H x 



eel diminishing year by year the sea-port towns of New En- 

 gland, which were formerly supported by this trade, now 

 showing the most evident indications of a fallin<^-off in the 

 business. 



In view of their great value to a nation, as an article of food 

 and trade, the great decrease in the numbers offish in many 

 parts of the w T orld has, as is w T ell known, invoked the atten- 

 tion of governments, as well as of private associations, to- 

 ward restoring the supply, this being capable of accomplish- 

 ment in two ways : first, by protection of the fish during the 

 critical season of spawning or migration, and by removing 

 the obstructions to their passage up the rivers, or elsewhere, 

 to their spawning-grounds ; and, secondly, by their artificial 

 propagation, securing the eggs and hatching these out, and 

 then rearing the young fish to a certain condition of matu- 

 rity, or else turning them at once into the water. The util- 

 ity of the second method depends, in a considerable measure, 

 upon. the fact that when fish spawn naturally, the eggs, in 

 large part, are improperly fertilized, and, consequently, do 

 not come to maturity, or else they are covered too deeply by 

 mud or gravel, or are devoured by the inhabitants of the wa- 

 ters ; and when the young actually succeed in escaping from 

 the egg, they are equally liable to attack and destruction. 

 But in the case of artificial hatching this result is measura- 

 bly avoided, the impregnation of the egg being accomplished 

 much more completely, and the eggs and young protected, 

 during the critical period, from their enemies. 



"While, therefore, it is estimated that only five per cent, of 

 the spawn naturally deposited by a fish in the water ever 

 pass beyond the stage of helpless infancy, in the case of arti- 

 ficial propagation the total loss up to the same stage should 

 not exceed five per cent. ; thus giving ninety-five per cent, 

 of the whole stock, instead of five per cent. The theory and 

 practice of fish-culture rests largely upon this consideration, 

 as also upon the fact that fish almost invariably return to 

 the spot where they first saw the light to lay their own eggs, 

 this making it possible, while introducing certain of the ana- 

 dromons fish into a stream, to calculate upon completely 

 stocking it after a few years. 



To carry out this desirable object of increasing the fish 

 supply, an appropriation was made by Congress to enable the 



