Fig. 44.—Lepidophloios Acadianus, Dawson, a lepidodendroid tree of the coal-formation, A, Restoration. B, Portion of bark (two thirds natural size), C, Ligneous surface of the same, F, Cone (two thirds natural size). G, Leaf (natural, size), K, Portion of woody cylinder, showing outer and inner series of vessels magnified, L, Scalariform vessels (highly magnified), M, Various forms of leaf-scars and leaf-bases (natural size).
Fig. 45.—Asterophyllites, Sphenophyllum, and Annularia. A, Asterophyllites trinerne. A1, Leaf enlarged, B, Annularia sphenophylloides. B1, Leaf enlarged, C, Sphenophyllum erosum. C1, Leaflet enlarged. C2, Scalariform vessel of Sphenophyllum. D, Pinnularia ramosissima, probably a root.
No one has done more than my friend Dr. Williamson, of Manchester, to illustrate the structure of Calamites, and he has shown that these plants, like other cryptogams of the Carboniferous, had mostly stems with regular fibrous wedges, like those of exogens. The structure of the stem is, indeed, so complex, and differs so much in different stages of growth, and different states of preservation, that we are in danger of falling into the greatest confusion in classifying these plants. Sometimes what we call a Calamite is a mere cast of its pith showing longitudinal striæ and constrictions at the nodes. Sometimes we have the form of the outer surface of the woody cylinder, showing longitudinal ribs, nodes, and marks of the emission of the branchlets. Sometimes we have the outer surface of the plant covered with a smooth bark showing flat ribs, or almost smooth, and having at the nodes regular articulations with the bases of the verticillate branchlets, or on the lower part of the stem the marks of the attachment of the roots. The Calamites grew in dense clumps, budding off from one another, sometimes at different levels, as the mud or sand accumulated about their stems, and in some species there were creeping rhizomata or root-stocks (Figs. [46] to [49]).
| Fig. 46.—Calamites. A, C. Suckovii. B, C. Cistii. (From “Acadian Geology.”) | Fig. 47.—Erect Calamites, with roots attached (Nova Scotia). | Fig. 48.—Node of C. Cistii, with long leaves (Nova Scotia). |
