. The microscope and its revelations. possession areshown in figs. 546-548. Thestem was of such large size that,in so small a part of the area ofits transverse section as is re-presented in fig 546, the medul-lary rays seem to run parallel toeach other, i listen d of radiatingfrom a common centre. They are FIG. 546.—Portion of transverse section ofvery narrow ; but are so closely larSe. stem of coniferous wood (fossil),, i ,1 ,1 i showing part of two annual rings, divided set together that only two or at fl> f° and traversed by ver£ thin but three rows of tracheids (no numerous medullary ra
. The microscope and its revelations. possession areshown in figs. 546-548. Thestem was of such large size that,in so small a part of the area ofits transverse section as is re-presented in fig 546, the medul-lary rays seem to run parallel toeach other, i listen d of radiatingfrom a common centre. They are FIG. 546.—Portion of transverse section ofvery narrow ; but are so closely larSe. stem of coniferous wood (fossil),, i ,1 ,1 i showing part of two annual rings, divided set together that only two or at fl> f° and traversed by ver£ thin but three rows of tracheids (no numerous medullary rays,ducts being here present) in-tervene between any pair of them. In the longitudinal sectiontaken in a radial direction (fig. 547), and consequently passing in thesame course with the medullary rays, these are seen as thin plates(«, «, a) made up of superposed cells very much elongated, andcrossing in a horizontal direction the tracheids which lie parallel toone another vertically. And in the tangential section (fig. 548), z z. 706 MICROSCOPIC STRUCTURE OF PHANEROGAMIC PLANTS which is taken in a direction at right angles to that of the medul-lary rays, and therefore cuts them across, we see that each of the
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
