88 



parts of the streams feeding them are still being more thoroughly taken 

 under ground. A good example of this is seen in the sinks just east of the 

 County Farm. The old sink is located in the angle of the road, while the 

 stream now passes beneath the surface fully a quarter of a mile upstream 

 to the northwest. Only the flood water now finds its way into the deeper 

 sink below. The collapse of the mouths of caverns is excellently exhibited 



Fig. 7. Shirley Spring (East Spring), S. B. of Leonard Schoolhouse. The 

 outlet of the stream entering the sinks east of the Poor Farm and the intervening 

 sinks. For abandoned, higher cave, see Fig. 30. The condition of collapse is similar 

 to that shown in Fig. 6. 



in the Shawnee caves east of Mitchell, Indiana, while Lost river shows it 

 still better. In both cases the roof has collapsed back for considerable 

 distances and in each there are cases of collapse above the mouths of the 

 ca^■erns where either the ca\e or the stream is brought to light. 



When this stage of the drainage has been reached sinks have developed 

 over most of the region on the interstream spaces as well as near the 

 streams and most of the drainage is subterranean in the stricter sense of 

 the word. This stage shows the large sinks near the larger drauiage lines, 



