. The geological history of plants. Paleobotany; 1888. 124: THE GEOLOGICAL HISTORY OF PLANTR he refere to Calamoju'tus, has woody bundles com- posed of reticulated or niultiporous tibres, with their porous sides pai-allcl to tlio mcdullai-y iiiys, which are better developed than in the previous form. The inter- vening cellular masses lu-e composed of elongated cells. This is a decided advance in structure, and is of the type of those forms having the most woody and largest stems, to ^. Fm. 49.—Eroot Oi/umi/K.* {C. Suekovii), showing the mode of growth of now stems (/)), and diftferont forms of
. The geological history of plants. Paleobotany; 1888. 124: THE GEOLOGICAL HISTORY OF PLANTR he refere to Calamoju'tus, has woody bundles com- posed of reticulated or niultiporous tibres, with their porous sides pai-allcl to tlio mcdullai-y iiiys, which are better developed than in the previous form. The inter- vening cellular masses lu-e composed of elongated cells. This is a decided advance in structure, and is of the type of those forms having the most woody and largest stems, to ^. Fm. 49.—Eroot Oi/umi/K.* {C. Suekovii), showing the mode of growth of now stems (/)), and diftferont forms of the ribs (a, o). (Piotou, Nova Sootla.) lliilf natural size. which Brongniart named Calamodendron (Fig. 50). A third form, to which Dr. Williamson seems to prefer to assign this last name, has the tissue of the woody wedges bai-red, as in the first, but the medullary rays are better developed than in the second. In this third form the intermediate tissue, or primary moduUury rays, is truly fibrous, and with secondary medullary rays traversing it. My own observations lead mo to infer that there was a fourth type of calamitean stem, loss endowed with woody matter, and having a larger fistulous or cellular cavity than any of those described by Dr. Williamson. There is every reason to believe that all these various. 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 Dawson, John William, Sir, 1820-1899. New York, D. Appleton and Company
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