FLORIDA REEFS 



405 



aerial roots in all directions, forming a tangle, whicli becomes effi- 

 cient in checking sediment-laden currents and causes them to de- 



FlG. 81. 



Map of Florida, showing the keys and reefs. (After Le Conte.) a — 

 Southern coast; a' — keys; a" — living reef; d-d' — older coral rock; 

 c — everglades; c' — shoal water; e" — ship channel; GSS — Gulf 

 Stream. 



posit their load. Hence the inner lagoon will gradually silt up, and 

 this has already progressed so far that a considerable portion of the 

 area forms mud flats at low tide. (Figs. 81, 82.) Here, then, a 



Fig. 82. Diagrammatic section of Florida along the line N.S. in the preceding 

 figure, showing the relative position of the various parts, lettering 

 the same. The dotted lines indicate hypothetical former condi- 

 tions. (After Le Conte.) 



