18* EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 

 r.— PEOPAGATION OF FOOD FISHES. 



10. — GENERAL CONSIDERATIONS. 



A patient whose constitution has been nnclermined by disease of long 

 continuance is unreasonable in expecting good results and a radical cure 

 after a short application of approved remedies, yet he and his friends 

 may be disajipointed if the recuperation from the excesses or lesions of 

 many years is not manifest in as many days. In reality, the reverse is 

 rather the rule, the time of recovery being more frequently mucli longer 

 than that of the continuance of the morbific influences. The expecta- 

 tions in regard to the resvdts of fish culture are of somewhat the same 

 character. Although decades of years, perhaps even a century, may 

 have withessed the continuance of agencies for the diminution of fish 

 in aur waters, the public mind is unsatisfied, and perliai)S inclined to 

 severe criticisms if the recovery of a supply is not appreciable within 

 the first two or three years of effort. 



We are, however, clearly entitled to maintain, in view of the exi:>e- 

 rience of foreign countries and our own, that no reasonable anticipation 

 in this respect will be disappointed, and that the proper measures of 

 legislation and of artificial propagation will exhibit a marked result long 

 before the end of the present generation. 



In no instance con even the beginning of a success be achieved in a 

 shorter period than four or five years, as the young, especially of the 

 .anadromous fish, such as the shad, the alemfe, and the salmou, require 

 that period for arriving at maturity. The parent fish are first obtained, 

 the eggs extracted and fertiUzed, and after being hatched out the young 

 are finally deposited in the waters to take their chances. Whatever be 

 the extent of time during which the i)rogeny remain in the river, they are 

 more or less withdrawn from observation, and it is only when the young 

 fish has reached full maturity and revisits its place of deposit for the i)ur- 

 pose of spawning that its presence is appreciated. It sometimes hap- 

 pens, too, that, for one reason or another, the first deposit of young 

 fish proves to be a failure. They may be introduced while in a sickly 

 condition, so that a difference of temperature causes them to succumb; 

 or else in such small numbers that in the presence of an unusual abun- 

 dance of enemies they may all perish. What special agencies there may 

 be in the ocean after they reach it we are unable to say ; but from their 

 wider dissemination their chance of escape is greater. 



Again, we may misunderstand the period required for the maturity of 

 certain species. While four years may be considered the general aver- 

 age for cod and herring, five are probably required for the Eastern sal- 

 mou, and it is not imi)ossible that the California salmon will show itself 

 only after the lapse of six years from its birth. I hope, however, to in- 

 troduce enough illustrations of even partial success to warrant the atten- 

 tion of Congress and of the States towards the operations of the Unitefl 



