464 ORIGIN OF THE APPALACHIAN COAL STRATA, 



suppose, that the whole period of the coal-measures was charac- 

 terized by a general slow subsidence of these coasts, on which we 

 conceive that the vegetation of the coal grew ; — that this vertical 

 depression, was, however, interrupted by pauses and gradual up- 

 ward movements of less frequency and duration, and that these 

 nearly statical conditions of the land, alternated with gi-eat parox- 

 ysmal displacements of the level, caused by those mighty pulsa- 

 tions of the crust which we call earthquakes. Let us further 

 conceive, that during the periods of gentle depression, or almost 

 absolute rest, the low coast was fringed by great marshy tracts or 

 peat-bogs, derived from and supporting a luxuriant growth of 

 Stigjuaiicc, and that along the land-ward margin, and in the drier 

 places of these extensive sea morasses, grew the Conifera;, Tree- 

 Ferns, LycopodicBcew, and other ai'borescent plants, whose remains 

 are so profusely scattered throughout the coarser strata between 

 the coal-seams. In this condition of things, the constant decom- 

 position and growth of the meadows of Stigmaricc, would pro- 

 duce a very uniform, extended stratum of pulpy but minutely 

 laminated pure peat. This would receive occasional contribu- 

 tions from the sheddings by the dispersed trees of their leaves, 

 fronds, and smaller portions, which, being driven by winds, or 

 floated on the high tides, would lodge among the Stigmarise in 

 the marshes, and slighdy augment the deposit. These leaves and 

 fronds, covered over more or less rapidly by the gi'owing Stig- 

 marifs, or varying in their tendency to decay, according to the 

 abundance or deficiency of their juices, would, when thus inclos- 

 ed, pass at once either to the pulpy state, and ultimately form 

 coal, or, by the more rapid extrication of their volatile portions, 

 remain as mineral charcoal, and preserve their vegetable fibrous 

 structure. In both of these conditions of coal and charcoal, we 

 often find the smaller parts of plants retaining their organized 

 forms among the laminae of the purest coal-seams. Upon this 

 view of a gradual accumulation from the Stig}na7ia;, assisted by 

 the deciduous parts of tlie trees, it is altogether unnecessary to 

 suppose, that any portions, even the upper layers of the coal-beds, 

 derived their vegetable matter from the stems of the trees them- 

 selves. Thus the absence of trunks and roots from the coal is 



