Bu!. 1105, U. S. DeDt. of Agriculture 



Plate III 



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Fig. I. 



Fig. 2. 



Figs. I and 2. — A Clay Flat on Which Reproduction Has Made Almost 

 Imperceptible Progress in I0 Years, Despite Adequate Seed Trees 

 and Complete Protection. 



The causes are a stone-free clav soil and a dense growth of bunchgrass. Upper photograph taken 



in 1909, lower in 1919. 



