178 TWELFTH ANNUAL REPORT OF THE 



completed. The water supply from lake sources has been greatly changed 

 for the better. The one great need of this station at present is some means 

 of utilizing the generous quantity of spring water available near the res- 

 idence. When this is properly introduced into the races and mingled with 

 the lake water so as to effectually control the temperature and prevent 

 those rapid fluctuations resulting in losses of young fish, the results of the 

 work will be greatly increased and its value enhanced. 



Lake water is proverbially subject to great fluctuations of temperature. 

 Even spring water varies so greatly in flow as to involve the stations in 

 unexpected mortality in seasons of drought. The Adirondack Hatchery 

 has a splendid resource in its large spring, and this 'can be utilized only by 

 pumping. The cost of pumping water, as demonstrated at the Constantia 

 station, is comparatively small, and there is no reason why the splendid 

 Adirondack station should not have recourse to this method 'of obtain- 

 ing cold water which is so essential to successful work in dry, warm 

 seasons. 



Foreman Winchester has preserved from time to time, and forwarded 

 to the office of the Commission, specimens of the water fauna of the hatchery 

 grounds. This fauna includes a number of animals which are commonly 

 regarded as injurious to fish life — such as Hydra, a fish louse, and a leech, 

 forms which are believed to destroy eggs and fry in greater or less numbers. 

 Mr. Winchester has made some recent observations on the Hydra, and has 

 reached the conclusion that it does not kill the trout fry to any considerable 

 extent, although it certainly destroys eggs by clinging to them and with- 

 drawing more or less of the fluid contents. At a Colorado station of the 

 United States a species of Hydra was observed to kill trout fry, and it may 

 be that the species at Upper Saranac will eventually be classed among the 

 fry destroyers. Mr. Winchester, however, has seen nothing so far to show 

 that the fry are injured by that animal. 



A gill parasite, commonly known as the fish louse, one of the degraded 

 forms of the copepods, is very injurious in its effects upon trout and especi- 

 ally yearlings, two-year olds and older fish. Unfortunately this is one 

 of the parasites which abound in all wild trout and salmon waters, and 

 which appear to be one of nature's checks on over production. The com- 

 mon Adirondack species was introduced into hatchery waters at Caledonia, 



