. Studies in fossil botany . Paleobotany. CALAMODENDRON 35 In fact, the principal rays are here much more complex in structure than the wood itself. The Calamodendron stems are especially characteristic of the Upper Coal- measures and Permian of Central France. This brings us to the question of nomenclature, on which I must say a word. Brongniart, in his earlier works, placed all the Calamitean stems then known to J * J" mr f. Y \ V. f 1G. 10.—Calamodendron intermedium. Part of transverse section of stem, showing inner portions of two vascular bundles, with secondary wood. /, pith ; /.r,
. Studies in fossil botany . Paleobotany. CALAMODENDRON 35 In fact, the principal rays are here much more complex in structure than the wood itself. The Calamodendron stems are especially characteristic of the Upper Coal- measures and Permian of Central France. This brings us to the question of nomenclature, on which I must say a word. Brongniart, in his earlier works, placed all the Calamitean stems then known to J * J" mr f. Y \ V. f 1G. 10.—Calamodendron intermedium. Part of transverse section of stem, showing inner portions of two vascular bundles, with secondary wood. /, pith ; /.r, protoxylem in canals of the bundles ; jr, fascicular wood, containing secondary rays ; f, prosen- chymatous parts of principal medullary rays ; ;«;-, central parenchymatous portion of each ray. .Magnified. After Renault. him in the one genus Calamites, and believed them to be related to the Equisetaceae; subsequently he investigated specimens with the internal structure pre- served, and in all clear cases of the kind he found a well-developed secondary wood. Wherever he found this, he thought he must have to do with a Dicoty- ledonous flowering plant of Gymnospermous affinities, for in those days Gymnosperms were usually included. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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