REPORT OF THE COMMISSIOK^ER OF FISHERIES. 19 



young blackspotted trout were returned to its waters during the 

 season. The Glacier Xational Park hatchery was well stocked with 

 eggs shipped from other hatcheries and produced therefrom an out- 

 put of over 2,000,000 fry and fingerlings of the brook trout, rainbow 

 trout, blackspotted trout, and grayling, in addition to approximately 

 450,000 fingerlings which were on hand at the close of the year. 



Under the handicap of exceedingly^ difficult natural conditions suc- 

 cessful rainbow trout collecting operations were conducted in Wyo- 

 ming on Sage Creek, Lost Creek, and Canon Creek, the two last 

 named being in fields which have never heretofore been exploited. 

 The results obtained, despite the very limited means available, ap- 

 pear to demonstrate beyond question the wisdom of establishing a 

 permanent collecting station on Sage Creek in order that the work 

 may be handled in a manner in some degree commensurate with the 

 potential value of the field. This stream is a tributary of the North 

 Platte liiA'er, and as the other streams mentioned are within a few 

 miles of it the eggs obtained from them and from other collecting 

 points in the Pathfinder reclamation project could be assembled and 

 incubated in a properly equipped hatchery on Sage Creek. 



The efficiency of the Spearfisli (S. Dak.) station has recently been 

 increased as the result of an arrangement with the cit}- authorities of 

 Spearfisli. Tender the provisions of a long-term lease the Bureau 

 has secured without cost all surplus water from a reservoir lately 

 constructed by the cit}'. While this arrangement is satisfactory and 

 gives the station an ample amount of water during the greater part 

 of the year, with a surpbis most of the tinus the supply falls to a 

 minimum during summer, when unusuall>' large amounts of water 

 are used for domestic purposes. In oi-der, th(>refore, to provide 

 against a shortage of water for the work at any season, it will be 

 advisable to pi-ovide a storage reserAoir for emergency use. A suit- 

 able reservoir can be constructed at small cost by placing a dam 

 in a canyon on property adjacent to the Bureau's reservation, and 

 Avith this additional outlay the station would be assured of an ade- 

 quate water supply for an indefinite period of time. 



In the propagation of the domesticated rainbow trout the results 

 show continued improvement as to l)oth quality and quantity of eggs 

 and fry. Small consignments of eggs taken from wild rainbow 

 trout at the western stations have been transferred to the eastern 

 hatcheries from time to time to maintain the virility of the brood 

 stock, and b}' this means no difficulty whatever is experienced in pro- 

 ducing this species in sufficient numbers to meet all requirements. 

 Recent anatomical studies of the rainl)0w trout conducted by the 

 division of scientific inquiry have disclosed a number of facts relating 

 to the reproductive organs of the female fish that have heretofore 

 been overlooked or were not understood at the hatcheries and may 

 have an important bearing on fish culture, especially with regard 

 to the manipulation of spawning fish. The experiments were con- 

 ducted at the W^'theville (Va.) station, and preparations have been 

 made to continue them indefiniteh^ at the Krwin (Tenn.) station, 

 or until the problems involved can be fully worked out. The scien- 

 tific division has also rendered assistance in overcoming the mor- 

 tality which usually occuis among adult trout at spawning time. 

 A careful examination of si)ecimons of trout dying during that time 



