THE SOILS OF FLORIDA. 31 
as implied by the name, are extremely numerous in this section of 
country. Surface streams are few, the rainfall passing into the 
soils. 
The lake region represents in the writer’s interpretation an early 
stage in the degradation of the surface level by underground solu¬ 
tion. The many basins now occupied by lakes have been formed by 
subsidence due to solution. Following the formation of the basins 
the surrounding uplands are gradually lowered, the tendency being 
to fill up the basins and to reduce the land surface once more to a 
common, although lower level. An examination of the accompany 
ing map on which the lake region is separately indicated shows 
that this region represents the further southeastward extension of 
the limestone country of the peninsula. 
The four topographic types described in the limestone country 
of the central part of the State are as follows: (1) The lake 
region, which represents an early stage of erosion in which 
deep circular lakes are surrounded by hills of approxi¬ 
mately the height of the original table land. (2) The ham 
mock belt, which includes flat-bottomed lakes, or lake bas'ns now 
occupied by prairie lands, surrounded by hills more or less lowered 
by erosion from the original level of the plateau. (3) The hard 
rock phosphate belt in which the formations that formerly overlay 
the Oligocene limestones have disintegrated, leaving only the mixed 
and complex residue. The phosphoric acid originally contained in 
the overlying formations has been taken into solution by perco¬ 
lating waters and reaccumulated at a lower level, forming the hard 
rock phosphate. (4) The fourth type is that designated as the Gulf 
Hammock land. In this section formations later than the lime 
stones, if formerly present, have disintegrated and have been en¬ 
tirely removed with the exception of an insignificant residue of 
loose sand. 
While the types described above are well-marked, there are inter¬ 
mediate stages and other variations arising from local conditions. 
The intermediate stages between the hammock belt of rolling red 
clay lands with large but shallow lakes, and the hard rock phos¬ 
phate belt with rolling sandy lands and no lakes, include rolling 
lands with more or less clay and with frequent or occasional sink 
hole lakes. 
TOPOGRAPHY CONTROLLED BY PLEISTOCENE LIMESTONES. 
The Pleistocene limestones of southern Florida for the most part 
lie so close to sea level as to exert no appreciable effect on the topog 
