122 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



outlet. They are. comparatively deep, and never go dry, though they 

 may fluctuate a few feet from one year to another with the amount 

 of rainfall. Many of the smaller ones at higher elevations beai 

 evidence, in the shape of young pine trees around their shores, ol 

 being a little lower now than they were a generation ago. (See 

 fig. 22). This may be due to a permanent lowering of the ground- 

 water level by numerous artesian wells with outlets at lower levels. 

 Unlike those in the lime-sink region and hammock belts, none of ttie 

 lakes are known to have any subterranean outlets. 



Streams are not very numerous, for most of the rainfall sinks 

 almost immediately into the deep sand which covers the uplands. 

 They are nearly all sluggish and coffee-colored. The St. John's and 

 Ocklawaha Rivers are navigable for small steamboats all the way 

 through the lake region, and being bordered by tropical-looking 

 vegetation, are favorite scenic highways. 



Fig. 20. Lake Alfred, a clear lake in the highlands of Polk County, show- 

 ing a fringe of maiden cane and bonnets a few yards off the sandy shore and 

 parallel with it. May 18, 1910. 



Soils. The soil of the uplands is mostly a slightly loamy sand 

 several feet deep, usually creamy or li^ht buff in color, but varying 

 to yellowish, brownish, and ashy gray, the last being found chiefly 

 a few miles south of Lakeland, near the edge of the pebble phos- 

 phate country. There is probably more pure white sand (scrub) in 

 this region than in any other, but there are no data yet for making 



