106 THE FARMER OF TO-MORROW 



are so many factors making for success or 

 failure for the Gleaner who casts his lot with 

 the settlers of the semi-arid plains that the 

 mere statement of ten or twenty inches of 

 rain means little in selecting a homestead. As 

 we have already seen, evaporation plays an 

 important part, being less rapid toward the 

 north, and therefore making the inevitable 

 task of conserving moisture more simple for 

 the farmer of the Dakotas than for the farmer 

 in Texas. 



Referring to this important factor in de- 

 termining the ultimate availability of the dry 

 lands, Lyman J. Briggs sums up as follows 

 (Bulletin 188, Bureau of Plant Industry, a 

 monograph on dry farming in relation to rain- 

 fall and evaporation) : 



"Dr. H. L. Shantz, of the Bureau of Plant 

 Industry, finds that the distribution of native 

 grasses is a good index of the rainfall require- 

 ments in the different sections of the Great 

 Plains. Short grass, which consists chiefly 

 of buffalo grass and grama grass, is well 

 suited for this purpose since it occurs from 

 Montana to Texas. In each section the grass 

 grows as far west as the opposing influences 

 of rainfall and evaporation will permit. The 

 growth of this short grass in the east is 



