1911-] STEVENSON— FORMATION OF COAL BEDS. 567 



N. L. 29°, but the peat deposits within southern Florida, as far 

 south as lat. 25° 30', are of great thickness, one dense cypress swamp 

 showing 20 feet. The Everglades of Florida embrace about 7,000 

 square miles, which must be regarded as considerable. Even be- 

 tween lat. 30° and 31°, there are thick deposits in which Sphagnum 

 is wanting or very rare. Cypress, grasses, fern, myrtle make up 

 most of the vegetation and provide material for peat. The water 

 hyacinth, recently introduced into one of the rivers, is now a peat- 

 maker and, in some localities, the peat is composed almost wholly 

 of this plant. 



The temperature conditions in the Bermudas are somewhat less 

 severe in summer than in southern Florida, for the summer heat 

 rarely exceeds 84° F. The southwest wind, blowing off the still 

 warm Gulf Stream, prevents low temperature and the humidity is 

 always high. On the main island there are two great swamps, one 

 of which has at least 50 feet of peat. The climate is such that 

 plants of Carboniferous type could grow well, for the banana thrives 

 while palms and the India rubber tree attain great size. 



The literature bearing on tropical swamps is very limited. Those 

 swamps, often of vast extent and covered with dense forest, are 

 regarded, rightly or wrongly, as malarial to the last degree, so that 

 they do not invite close examination on the part of travellers. Yet, 

 even in the limited literature, one finds ample proof that, when the 

 necessary condition of topography and continuous moisture prevail, 

 peat does form. 



Wall and Sawkins*^* estimate the swamp area of Trinidad at six 

 per cent. The long dry season is not favorable to the accumulation 

 of peaty materials ; yet the Nariva swamp, drained by streams flow- 

 ing 12 to 15 feet below the general level, has a black soil which after 

 desiccation at 300° F. still yielded 35 per cent, of organic matter. 

 Hartt°^ found peat in the state of Sao Salvador, Brazil, S. L. 10°. 

 He states distinctly that he found peat. " A quarter of a mile south 



"^ G. P. Wall and J. G. Savvkins, " Geology of Trinidad," London, i860, 

 pp. 62, 63. 



"^ C. F. Hartt, " Geology and Physical Geology of Brazil," Boston, 1870, 

 pp. 365, 509- 



PROC. AMER. PHIL. SOC, I.. 202 I, I., PRINTED NOV. 1 6, I9II. 



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