ACKNOWLEDGMENT 



This report is a summary of the experi- 

 ments conducted in 1959 and 1960. The 

 Leavenworth hatchery personnel assisted this 

 study materially. We are particularly grateful 

 to manager Alfred C. Gastineau and his 

 assistant, Clifford W. Dickeson, for their 

 outstanding cooperation. 



LITERATURE CITED 



BHATIA, D. 



1931. On the production of annual zones 

 in the scales of the rainbow trout 

 Salmo irideus. I. Journal of Experi- 

 mental Zoology, vol. 59, no. 1 (Feb- 

 ruary), p. 45-59. 



1932. Factors involved in the production 

 of annual zones on the scales of the 

 rainbow trout Salmo irideus 11. Jour- 

 nal of Experimental Biology, vol. 9, 

 no. i (January), p. 6-11. 



GRAY, J., and S. B. SETNA. 



1931. The growth of fish. IV. The effect 

 of food supply on the scales of Salmo 

 irideus. Journal of Experimental 

 Biology, vol. 8, no. 1 (January), p. 55- 

 62. 



HEWITT, GEORGE S., and ROGER E. 



BURROWS. 



1948. Improved method for enumerating 



hatchery fish populations. Progressive 



Fish-Culturist, vol. 10, no. 1 (January), 



p. 23-27. 



MS #1162 



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