Bul. 1227, U. S. Dept. of Agriculture. PLATE III. 
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FiG. |1.—UNDER TOTAL PROTECTION. 
The difference in the number of fruiting heads under protection and under rodent grazing 
indicates the difficulties of propagation by seeds when prairie dogs are present. 
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Fic. 2.—UNDER GRAZING BY PRAIRIE DOGS. 
The grass is thinner and poorer than under protection from the rodents. The background in 
this figure and in Figure 1 is numbered in feet. 
WHEATGRASS (AGROPYRON SMITHII) UNDER TOTAL PRO- 
TECTION AND UNDER GRAZING BY PRAIRIE DOGS, COCO- 
NINO, ARIZ., OCTOBER 29, 1920. 
