THE EVERGLADES 119 



bee, which for a distance is the northern limit of 

 the Everglades, the land is elevated twenty feet 

 above sea level. From the lake it gradually 

 slopes southwesterly to the Gulf of Mexico, also 

 southerly to the Bay of Florida, and finally south- 

 easterly to the FloridaiStrait. Muck, peat, and sand 

 form most of the normal surface of the great swamp 

 and these rest on a foundation of soft limestone. 

 For ages the rains have been dissolving this rock, 

 forming pools which afterwards became ponds 

 and lakes. A rank growth of herbaceous vegeta- 

 tion has occupied these basins and in decasdng 

 has slowly filled them with muck and peat. The 

 region about Okeechobee was elevated long before 

 that farther south, hence the lake or pond basins 

 of that area with a longer time for the process were 

 dissolved out to greater depths, and became more 

 or less filled with vegetable deposits. Lakes Flirt 

 and Hicpbchee are nearly silted to the water level 

 and were once, most likely, a part of the great lake. 

 The southern part of the Glades was recently 

 elevated and there has not been suflficient time as 

 yet to dissolve out any considerable basins, or to 

 form any great depth of vegetable deposits. In 

 fact the rock appears on the surface over extensive 



