...Stigmaria underclay ; its bark the compact coal; its woody axis the mineral charcoal; its fallen leaves, with remains of herbaceous plants growing in its shade,...also probable that the comparative impermeability of bark to mineral infiltration is of importance in this respect, enabling this material to remain unaffected...

...Stigmaria underclay ; its bark the compact coal ; its woody axis the mineral charcoal ; its fallen leaves, with remains of herbaceous plants growing in its shade,...earthy matter, the layers of coarse coal. The condition the durable outer bark of erect trees concurs with the chemical theory of coal, in showing the especial...

...Stigmaria underclay ; its bark the compact coal ; its woody axis the mineral charcoal ; its fallen leaves, with remains of herbaceous plants growing in its shade,...also probable that the comparative impermeability of bark to mineral infiltration is of importance in this respect, enabling this material to remain unaffected...

...an erect forest, presents an epitome of a coal-seam. Its roots represent the Stigmaria under clay ; its bark the compact coal ; its woody axis, the mineral...concurs with the chemical theory of coal, in showing the suitableness of this kind of tissue for the production of the purer compact coals. It is also probable...

...stigmaria underclay ; its bark the compact coal ; its woody axis the mineral charcoal ; its fallen leaves, with remains of herbaceous plants growing in its shade,...with a little earthy matter, the layers of coarse coal."1 Some further information as to the occurrence of spores in coal is contained in a contribution...

...centre, and into these the almost pointed ends of the rootlets fitted as by a ball and socket joint. "A single trunk of sigillaria in an erect forest presents...tissue for the production of the purer compact coals." — Dawson, "Structures in Coal." There is yet one other family of plants which must be mentioned,...

...centre, and into these the almost pointed ends of the rootlets fitted as by a ball and socket joint. ''A single trunk of sigillaria in an erect forest...of tissue for the production of the purer compact coals."—Dawson, "Structures in Coal." There is yet one other family of plants which must be mentioned,...

...forest presents an epitome of a coal-seam. Its roots represent the FIG. 17.— Section of stigmaria. stigmaria underclay ; its bark the compact coal ;...tissue for the production of the purer compact coals." — Dawson, "Structures in Coal." There is yet one other family of plants which must be mentioned,...

...forest presents an epitome of a coal-seam Its roots represent the FIG. 17. —Section of stigmaria. stigmaria underclay; its bark the compact coal; its...of tissue for the production of the purer compact coals."-—Dawson, "Structures in Coal." There is yet one other family of plants which must be .mentioned,...

...in an erect forest presents an epitome of a coal-seam. Its roots represent the stigmaria underday ; its bark the compact coal ; its woody axis the mineral...tissue for the production of the purer compact coals." — Dawson, " Structures in Coal." There is yet one other family of plants which must be mentioned,...