THE ARTIFICIAL PROPAGATION OF SEA-FISHES. 363 



can long survive the attacks of a new unnatural enemy armed 

 with the energy, the resources, and the intelligence of civilized 

 man. Fortunately, the qualities which render him the most resist- 

 less of enemies also enable him to become a producer as well as a 

 destroyer ; and, while the fear of him and the dread of him is 

 upon every beast of the earth and upon every fowl of the air and 

 upon all the fishes of the sea — while they are all delivered into 

 his hands, and are powerless to resist him — he alone of all animals 

 is able to make good the destruction caused by his ravages, and 

 to increase, by agriculture, by domestication, by selection and im- 

 provement, and by artificial propagation, the animals and plants 

 which he destroys. 



Can these influences be brought to bear upon marine animals ? 

 Can human intelligence and skill and power over Nature be so 

 employed as to make quickly, by artificial means, that slight ad- 

 justment in the birth-rate of food-fishes which would have been 

 brought about more slowly by natural agencies if man had long 

 occupied his present rank among their enemies ? 



Looked at in this way, the proposition certainly does not seem 

 to be impracticable; and, while human efforts in this field are of 

 too recent a date to furnish positive evidence, I believe that I have 

 shown that there is no a priori impossibility and no logical basis 

 for a negative answer to the question. The results which have 

 already been reached by the artificial propagation of certain sea- 

 fishes, like the shad, which make periodical visits to fresh water, 

 are extremely interesting, as they furnish indirect evidence which 

 is very conclusive. They prove that human influence produces 

 very prompt and decidedly advantageous results in the case of 

 these fishes, and thus give us every reason to hope that equally 

 valuable results will follow — a little more slowly, perhaps — from 

 our efforts to increase the supply of more strictly marine species. 



In the year 1880 the fisheries census and special investigations 

 which were carried on under the direction of the United States 

 Fish Commission proved that there had been a most rapid and 

 alarming decline in the value of the shad-fisheries in the rivers 

 and bays and sounds of our Atlantic coast, and that there was 

 every reason to fear that in a few years the shad would be utterly 

 exterminated. The adult shad is an oceanic fish, but each spring 

 it enters one of the inlets or bays and makes its way up to the 

 fresh-water streams to reproduce its kind. The supply of shad for 

 the market is caught during this spring migration, when the fishes 

 enter our inland waters plump and fat after their winter's feast 

 upon the abundant supply of food which they find in the ocean. 

 As they spend the greater part of each year gathering up and 

 converting into the substance of their own bodies the innumerable 

 minute marine organisms which would be of no value whatever to 



