RESEARCH REPORTS 



This series of reports was begun wlien tlie Fish and Wildlife Service was established 

 in 1941 ; the series superseded AVildlife Research Bulletins of the Bureau of Biological 

 Survey and Investigational Reports of the Bureau of Fisheries, those two Bureaus 

 having merged to form the Service. Research Reports 1 to 53 were published by the 

 Fish and Wildlife Service. The series has been continued, from Research Report 54 

 onward, in a slightly changed format, as the research-reporting series of the Bureau of 

 Sport Fisheries and Wildlife, comprising reports of scientific investigations related to 

 the work of the Bureau. The Bureau distributes these reports without charge to 

 oflBcial agencies, to libraries, and to researchers in fields related to the Bureau's work ; 

 additional copies may usually be purchased from the Division of Public Documents, 

 U.S. Government Printing OflBce. 



Current Research Reports are — 



54. Fluctuations in Age Composition and Growth Rate of Cutthroat Trout in Yellow- 



stone Lake, by Ross V. Bulkley. 1961. 31 pp. 



55. Mortality Studies on Cutthroat Trout in Yellowstone Lake, by Orville P. Ball and 



Oliver B. Cope. 1961. 62 pp. 



56. Limnology of Yellowstone Lake in Relation to the Cutthroat Trout, by Norman G. 



Benson. 1961. 33 pp. 



57. Chemical Composition of Blood of Smallmouth Bass, by Eddie Wayne Shell. 1961. 



36 pp. 



58. Chronic Effects of Endrin on Bluntnose Minnows and Guppies, by Donald Irvin 



Mount. 1962. 38 pp. 



59. Predicting Year-Class Abundance of Yellowstone Lake Cutthroat Trout, by Ross V. 



Bulkley and Norman G. Benson. 1962. 21 pp. 



60. Limnological Organic Analyses by Quantitative Dichromate Oxidation, by John A. 



Maciolek. 1962. 61 pp. 



61. Bioassay and Use of Pituitary Materials to Spawn Warm- Water Fishes, by Howard 



P. Clemens and Kermit E. Sneed. 1962. 30 pp. 



62. Equilibrium Yield and Management of Cutthroat Trout in Yellowstone Lake, by 



Norman G. Benson and Ross V. Bulkley. 1963. 44 pp. 



63. Sea-Water Systems for Experimental Aquariums ; A Collection of Papers, edited 



by John R. Clark and Roberta L. Clark. 1964. 190 pp. 



64. Some Chronic Effects of DDT on Cutthroat, Trout, by Don Allison, Burton J. 



Kallman, Oliver B. Cope, and Charles Van Valin. 1964. 30 pp. 



