44 Ticciify-sCi'cntli Annual Meeting 



If natural reproduction be so sliglit under the most favorable 

 conditions — such favoring state being simply a natural environ- 

 ment^how much less must be procreative results after balance 

 has been destroyed, in the depletion of a species without corre- 

 sponding reduction in numbers of its coinhabitants; certainly 

 chances against natural reproduction of a class thus depleted 

 would be multiplied — ^in fact, it will cease to be natiu-al simply for 

 the reason that the run-down species is handicapped by existence 

 of unnatural conditions. Such conditions now prevail. 



It is conceded, I think, that the greatest natural waste occurs 

 during the period of incubation ; beginning immediately after ex- 

 trusion of the ova. During this period more than 99 per cent, 

 of whitefish ova is wasted, through destructive agencies, or lack of 

 fecundation. Tlius, the procreative efforts of two adult whitefish 

 would probably be represented by less than loo fry. Xow, it 

 seems equally probable that less than i per cent, of these fry 

 reach maturity. If it were otherwise, over-production would en- 

 sue — that is. if in a pristine state of nature, procreative efforts of 

 fishes duplicate or double their adult numbers yearly, their habitat 

 would quickly become over-populated — in other words, the wa- 

 ters would not hold them. The sequence is obvious — it means 

 that a pair of adult fishes, working under strictly natural condi- 

 tions, will add less than an average of one re])resentative of their 

 kind yearly, which lives to reach maturity. 



Let us now get at approximate results of artificial propaga- 

 tion of whitefish. It is a well-known fact that an average of at 

 least 70 per cent of artificially handled ova from this species 

 hatches. Allowing a loss of 10 per cent, of the fry in transporta- 

 tion and from other causes, leaves 60 per cent, of the entire num- 

 ber of eggs produced by an adult whitefish, to be returned to the 

 waters in the form of vigorous fry. In brief, a pair of mature 

 whitefish taken from their spawning bed, compensate by a return 

 of 16,000 active fry, as a result of artifice. 



Now we will consider the chances for and against the matur- 

 ing of hatchery products. Incubation proceeded, in hatcheries, 

 in water of a natural temperature; the period being neither shorter 

 nor longer than under natural conditions. In transition from 

 hatchery to habitat, the same conditions obtain. .Scientific re- 

 search develops the ubiquity of organic forms, on which the fry 

 of whitefish subsist. Carefully conducted experiments also prove 

 that hatchery products quickly detect such matter, profiting to 

 the extent that substantial growth is quickly apparent. Thus, '-n 

 the battle for existence, the products of our hatcheries are placed 



