THE BUILDING OF THE LAND 27 



Eventually a weakened roof collapses over 

 one of these water passages but the debris is soon 

 dissolved and washed out and in time an open 

 passage from ocean to bay is formed. There 

 will be deep holes and shallows in these passages, 

 and along their banks mangroves may find lodg- 

 ment, sometimes even on the bare rock. The 

 tides rush through the newly made passage con- 

 stantly eating away its banks until the two sides 

 are widely separated. Many if not all the keys 

 have been more or less divided in this manner and 

 are still being worn away. The Ragged Keys, 

 a set of rocky islets at the northern end of the 

 chain (and most appropriately named) , are striking 

 examples of this scouring and dissolving power 

 of the sea. According to A. J. Sands and Otto 

 Matthaus, both long residents of the region, 

 Ragged Key Rock was, but a few years ago, about 

 fifty feet across and supported trees and shrubs. 

 The sea completely undermined it and then a 

 severe storm completed the wreck. Now there 

 remains but a small rock visible at low tide. It 

 is not unlikely that within a few centuries past 

 this now submerged rock was a part of a long island 

 lying to the south of it. The present gradual sub- 



