ECOLOGICAL STUDY OF DRY RUN 



119 



in dry weather. The author has never seen the stream dry up com- 

 pletely above this point, although he has watched through a number 



Fig. 20. — Usual appearance of uppermost quarry. 

 ?hown in lower left hand corner. 



Water disappears in region 



Fig. 21. — View of walls of uppermost quarry. Notice great difference in tex- 

 ture of strata. Layers 2 and 7 are harder than the others. 



of exceedingly dry seasons. The sink hole shown in figure 17 is cir- 

 cular and about five feet across. It is surrounded by large bowlders 

 and is filled with smaller loose fragments of limestone. When the 



