170 FLORIDA GEOLOGICAL SURVEY-I3TH ANNUAL REPORT

 Most streams in our area are too short or too near sea-level to fluctuate much with the seasons, and besides the excess of rainfall in late summer (see chapter on climate, farther on) tends to counterbalance evaporation and thus keep their flow uniform, so that floods are practically unknown. The St. John's River, the largest, is unique in several ways. It rises in great marshes or wet prairies, resembling the Everglades, near the southern edge of Bre.vard County, within 25 miles of the ocean in a direct line and not ovei 20 feet above it at low water, and flows northward approximately parallel to the coast for over 200 miles, with a fall of only about an inch to the mile. In the latitudes under consideration it is much narrower than it is where influenced by the tide, except where it expands into lakes. Lake Monroe, between Sanford and Enterprise, is said to be five feet above sea-level, with a maximum depth (at low water?) of only eight feet. Between there and Lake Harney, the next lake above, the river is said to have an extreme fluctuation of seven feet, which is perhaps the greatest of any stream in central Florida, unless it is exceeded by the Peace or the Alafia River; but that of course is very -little compared with some of the rivers farther north.
 The Ocklawaha* and Withlacoochee Rivers resemble the St. John's in flowing northward most of their length, a phenomenon that deserves more attention from physiographers than it has received.
 SOILS
 The soils of central Florida, although prevailingly sands, are considerably diversified within certain limits. Alluvial and red. clayey soils are scarce, but we have soils ranging in chemical composition from nearly pure calcium carbonate and highly phosphatic to nearly pure silica and peat.
 The correlations between soil and vegetation in this part of the country are so close, and the natural vegetation nearly everywhere so prominent, that most previous attempts to classify Florida soils

 *In recent years this has often been spelled "Oklawaha," presumably by the same sort of people who write "Suwanee' for Suwannee, "Hillsboro" for Hillsborough, "Okechobee" for Okeechobee, etc., but this should especially be discouraged, for it tends to give an erroneous impression of the first syllable. (For the benefit of strangers it might be well to explain that the main accent is on the third syllable. Also that Kissimmee is accented in the middle.)