Bul. 1227, U. S. Dept. of Agriculture. 
PLATE IV. 
Mee 
Soa 9) a 
7". 
Sa 
ef 
Fiac. |.—UNDER TOTAL PROTECTION. 
In the plot from which prairie dogs and stock were excluded tall stems and fruiting heads 
developed. (Measurements in the background are in feet.) 
FIG. 2.—UNDER GRAZING BY PRAIRIE DOGS. 
Grazing by prairie dogs usually reduces this grass to the form of a close-set turf, with few or no 
tall stems and frequently no fruiting heads whatever. 
BLUE GRAMA (BOUTELOUA GRACILIS) 
UNDER TOTAL PRO- 
TECTION AND UNDER GRAZING BY PRAIRIE DOGS, COCO- 
NINO, ARIZ., OCTOBER 29, 
1920. 
