DAMAGE TO RANGE GRASSES BY THE ZUNI PRAIRIE DOG 15 
LITERATURE CITED. 
Bett, W. B. 
1921. Death to the rodents: U. 8S. Dept. Agr., Yearbook 1920, pp. 421-4388 ; 
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CLEMENTS, F. E. 
1505. Research methods in ecology: Lincoln, Univ. Pub. Co., pp. xvii+334, 
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1920. Plant indicators: the relation of plant communities to process and 
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HO.Luister, N. 
1916. A systematic account of the prairie dogs: U. S. Dept. Agr., Bur. 
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LOFTFIELD, J. V. G. 
1924. Plant successions on grazing ranges in northern Arizona. (In MS.) 
MERRIAM, C. HART. 
1902. The prairie dog of the Great Plains: U. S. Dept. Agr., Yearbook 
1901, pp. 257-270, pls. 22-24, figs. 24 and 25. 
NELtson, E.. W. 
1918. Annual report of chief of Bureau of Biological Survey (pp. 1-19): 
Jn Annual reports of the Department of Agriculture for the year 
ended June 30, 1918, pp. 257-275, 1919. 
1919. Annual report of chief of Bureau of Biological Survey (pp. 1-24): 
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ended June 30, 1919, pp. 275-298, 1920. 
SHaw, W. T. 
1920. The cost of a squirrel and squirrel control: Agr. Exp. Sta., State 
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