Peninsular Florida is really an island, being separated from the 

 Southern Pine parklands by the St. Marys River, the Okefenokee 

 Bog, and the Suwannee River and swamps. Geologically 

 it is a new land, having been formed around a string of low 

 islands and reefs during Pleistocene times by the materials 

 washed off the eastern Appalachian piedmont and moved down 

 the coast by inshore marine countercurrents. It now forms a 

 low-domed ridge, never rising over 350 feet above sea level. 

 This peninsula is divided into a number of north-to-south 

 strips — six in number in the north, three in the extreme south — 

 each different and each subdivided into sections from East 

 to West. Along the whole Atlantic coast there is a fringe 



of sand dunes and beaches; inland from these lie, in the north, 

 a long belt of swamps about the St. Johns River; and south 

 of this, a low plain dotted with pines, called "flatwoods." The 

 next strip west constitutes the spine of the peninsula; it starts in 

 the north in the form of low. subdued hills formed by the 

 ancient islands and reefs, but then gives way throughout the 

 central area to low. rolling country dotted with innumerable 

 lakes and culminating in big Lake Okeechobee. South of this the 

 country changes to the so-called "Everglades," which are vast 

 open saw grass marshes dotted with low islands, locally called 

 "hammocks" but elsewhere "hummocks." These do not reach the 

 coast at any point. 



To the west of this central spine lies another long strip 

 of flatwoods, but in the north this contains a unique stretch 

 known as the limestone sinkhole belt that turns northwest, 

 crosses the Suwannee River, and continues on into the Florida 

 panhandle. To the south of the Caloosahatchee River, which 

 drains west out of Lake Okeechobee, the flatwoods devolve into 

 a huge swamp known as the Big Cypress. Finally, along the Gulf 

 or west coast, is a fringe of swampland broken by mud flats, 

 reed-filled estuaries, and sand beaches, and cut by three major 

 swamps — the lower Suwannee, the Hillsborough River Flats, and 

 the edge of Big Cypress. The southern extremity of this area, 

 south of Big Cypress, is a mangrove swamp fringed by 

 mangrove-covered islands named the Ten Thousand Isles. This 

 curls round the southern tip of Florida to meet the Atlantic 

 sand beaches, which then extend for a hundred miles southwest 

 in the form of a long string of small cays. 



This peninsula may be divided on phytogeographical grounds 

 into three belts running from west to east. The northern is part 

 of the Parklands Belt; the central a continuation of the Prairies; 

 and the southern an outlier of the Northern Scrub Belt. The 

 last is often referred to as being "subtropical," but it lies north of 

 the Tropic of Cancer, which is today regarded as the northern 

 limit of the subtropics. 



body of the country, but goes right on into the Caribbean and 

 appears at the surface again in the Greater Antilles. The rest of 

 the province has been built up around this ridge in easy stages 

 during what geologists call the Pleistocene or "glacial" and the 

 Holocene or "postglacial" periods, covering a time period of 

 only a million years. The limestones of the ridge were laid 

 down in a warm sea much earlier than this. 



They have all the usual characteristics of limestones, one of 

 which is that they may be dissolved by the carbonic acid con- 

 tained in rain water. This surface water, soaking down into these 

 strata, tends first to form little runnels along the natural cracks 

 in the rocks, then to expand these into channels and finally into 

 a network of caves. These in turn continue to enlarge, and if they 

 are near enough to the surface of the land, their roofs sometimes 

 collapse, resulting in what are called sinkholes. 



The astonishing thing about such sinkholes in Florida is that 

 the water may flow up out of them rather than down into them. 

 Silver Springs, near Ocala, is an interesting example. This is a 

 large "boil," and its point of water outflow is about seventy feet 

 below the land surface. There is a considerable cave here, and 

 from the floor of this the fossilized and semifossilized bones of 

 several animals have been taken by skin divers; these include 

 bones of mastodons and of another elephantine creature. It is a 

 beautiful place, its waters especially so. 



But I know of another "boil" with numerous clear effluents that 

 is not too far away from this place and is even more beautiful, 

 being so far altogether untouched by commercialism or other 

 human activities. It also centers around a large spring but one 

 not so deep, and h has three main exits. Its water too is absolutely 

 clear and filled with little nondescript fish, many large gars and 

 alligators, several varieties of water tortoises, and other clear- 

 water creatures. It is surrounded by swampy-looking but firm 

 land grown with cypresses, pines, and oaks, all festooned with 

 Spanish Moss. There is much natural grass along its verges, and 

 its waters are filled with waving, dark green, aquatic plants, 

 while acres of water lilies and other vegetable things float upon 

 its surface. To swim in this water below the surface is to enter 

 a land of complete perfection and considerable mystery. The 

 bottom is pure white sand; and, using a pair of goggles only, you 

 will here find yourself in the most intimate contact with all 



Above: A species of Flamingo that nests in Florida. In low 

 water they scoop mud toward their feet, pick it up with 

 their bills backward and upside down, and then filter out 

 edible material. Below: The Purple Gallinule (Porphyrula 

 martinica), one of the most colorful and "impertinent" of 

 birds, walks about on lily pads in swamps. 



Y74 



