. Off-hand sketches : a companion for the tourist and traveller over the Philadelphia, Pottsville, and Reading railroad . FIG. 15.—CRASSULA TETRAGONA. which, in these plants, is conveyed in myriads of small cuticularpores, to the cellular tissue which lies beneath them. The Calamites are not analogous to any existing species, as alreadynoted, though they resemble some plants in structure, but differwidely in their proportions—the fossil indicating large trees, whilethe existing species which they resemble are but two or three feethigh, and of corresponding diameter. Of the coniferse of the coa
. Off-hand sketches : a companion for the tourist and traveller over the Philadelphia, Pottsville, and Reading railroad . FIG. 15.—CRASSULA TETRAGONA. which, in these plants, is conveyed in myriads of small cuticularpores, to the cellular tissue which lies beneath them. The Calamites are not analogous to any existing species, as alreadynoted, though they resemble some plants in structure, but differwidely in their proportions—the fossil indicating large trees, whilethe existing species which they resemble are but two or three feethigh, and of corresponding diameter. Of the coniferse of the coal, it has been observed that they bear astrong resemblance to existing ^mes—slices of the wood, when examinedby the microscope, showing that theducts or glands peculiar to thisfamily of trees, are arranged in asimilar manner, that is, alternatelyin double and triple rows, fig. stigmaria is generally sup-posed to have been a large succulent water-plant—the stem, in itscompressed fossil state, varying from two to six inches in diameter,and has numerous processes, which proceed vertically, horizontally. FIG. 16.— ANTHRACITE COAL FORMATION 131 and obliquely, and traverse the beds in every direction. These pro-cesses have been traced to a distance of eight or ten feet from thestem, and had a horizontal range of twenty feet. From the extra-ordinary number of these plants, it is concluded that they havefurnished the material for the great bulk of our coal bods. From the general character of the vegetation, and the absence ofthe great mountain ranges which now conspicuously mark the earthssurface, it is probable that water covered a far greater area of countrythan it subsequently did, while, at the same time, its mineral quali-ties must have been essentially different from what they are now.
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Keywords: ., bookcentury1800, bookdecade1850, bookidoffhandsketc, bookyear1854
