

204 BOTAXICAL GAZETTE [march 



as shown in fig. 12. This pictures a microscopical section of 

 bituminous coal from Perry County, Ohio. Crinkled bands of 



com 



figu 



coal are present as flattened spores, appearing as light bodies im- 

 bedded in a dense black amorphous matrix. Both the lignitic coal 



amount 



material in addition to the more obviously lacustrine derivatives, 

 such as spores, etc., which have been shown to be characteristically 



amp peats. It seems 



must 



similar process, and for this reason any coal showing a high spore 

 content should be considered as having been formed in the same 

 manner which obtains in present deposits; that is, in open water, 

 and not by an accumulation of fallen plants in situ, as stated by 

 the older geological publications upon this subject (1, 5, 11, 14* 1 5)- 

 Since it is generally admitted that natural factors, such as 

 climate and topography, have been instrumental in the formation 

 of our coal beds, it is obvious that a correlation between past and 

 present phenomena is essential for a precise understanding of ancient 

 and modern peat deposits. In regard to climate, competent investi- 

 gators are quite agreed that there was a somewhat warm and humid 

 atmosphere over the earth during the Carboniferous and later 

 peat-forming epochs. This supposition is corroborated by obser- 

 vations of fossil remains characteristic of the different periods which 

 show a usual lack of annual rings. The nearest parallel to these 

 climatic conditions of growth is now found to prevail only in semi- 

 tropical and tropical regions. Because of the importance of these 

 considerations, the writer has chosen many of his illustrations from 

 the semitropical peat deposits of Florida, since they present a 

 closer analogy to coal beds than do the more northern organic 

 strata. It has already been pointed out that there is a sur- 

 prising lack of autocthonous accumulations in this locality in 

 contrast to an abundance of lacustrine deposits. This dearth of 

 land-formed peat is clearly dependent upon the rapid decay of 

 exposed land plants in zones without a winter season. Accelerated 

 disintegration under these conditions is sufficiently pronounced to 









