PRELIMINARY REI'ORT ON PEAT.

fronted at the outset with what appears to be a serious difficulty; namely such prominent features as lakes, hammocks,* flatwoods, prairies, lime-sinks, scrub, etc., are widely scattered over the state, in what might seem at first to be inextricable confusion. But by careful study it is possible to locate a well-defined lake region, a lime-sink region, two or three hammock regions, several flatwoods regions, etc.
Before defining these regions it will be well to explain in a few words the geological structure of Florida. The entire State is underlaid by limestone, of various ages from Vicksburg to Recent, and that is covered in most places by several feet of clay (mostly Pliocene ) or sand (mostly Pleistocene) or both. The character of the country at any particular place is determined principally by the amount of clay or sand on top of the limestone, the elevation above sea-level, the time elapsed since it last emerged from beneath the sea, and the average d(, th of the ground-water below the surface.
(Tiese characters in turn are all more or less dependent on each other, in various intricate ways).
The map accompanying this report (plate I6) divides the State i1,o about twenty geographical divisions of varying rank, some of them more distinct than others. Some which are very small, or imperfectly understood, or which contain little or no peat, are shown merely for the sake of completeness, and foi suggestions to future explorers, and will not be described in the text.
It is scarcely necessary to remark that this map is only a preliminary one, and future investigations may change it considerably. For some of the boundaries are rather vague at the best. and even where they are very distinct their location has been verified only at a comparatively few points (such as where they are crossed by railroads), and guessed at the rest of the way. Moreover, there will always be differences of opinion as to how far the process of subdivision should be carried, as is the case in nearly all classifications of things.
*Many residents of other states who have written aboit Florida have attempted to define "hammock" (a term which is used in Florida more than in all the rest of the world), but most of them have missed the mark by trying to correlate it with soil. A hammock is nothing more nor less than a certain type of vegetation: namely, a comparatively dense growth of trooe other than pines, in comparatively dry soil (or at least not wet enough to he called a swamp), in a region where open pine forests predominate. The ground in such places is always covered with more or less humus derived from the trees, but immediately under the humus the soil may be either sand, clay, marl or limestone. An intermediate condition between hammock and swamp is often called low hammock. The desirability of hammock land for agricultural purposes is due primarily to its humus.

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