. The anatomy of woody plants. Botany -- Anatomy. 86 THE ANATOMY OF WOODY PLANTS It will be advantageous as a sequel to the representation of the prominent types of rays in the dicotyledons in diagram to view them in actual photographs in the case of the genus Casuarina. We may profitably begin here, as in the case of the diagrams, with transverse sections. Fig. 65 reproduces the cross-section of a small twig of Casuarina Fraseri. The leaves are in the main still present in depressions on the surface of the stem and clearly sub- tend the foliar rays. Rather nar- row leaf gaps pene- trate the f
. The anatomy of woody plants. Botany -- Anatomy. 86 THE ANATOMY OF WOODY PLANTS It will be advantageous as a sequel to the representation of the prominent types of rays in the dicotyledons in diagram to view them in actual photographs in the case of the genus Casuarina. We may profitably begin here, as in the case of the diagrams, with transverse sections. Fig. 65 reproduces the cross-section of a small twig of Casuarina Fraseri. The leaves are in the main still present in depressions on the surface of the stem and clearly sub- tend the foliar rays. Rather nar- row leaf gaps pene- trate the first annual ring and are twice as numer- ous as the append- ages at a given node (that is, there are twelve gaps, although only six appendages) . This duplication of the gaps is due to the fact that the whorls of leaves alternate at differ- ent nodes, and the gaps correspond- ing to these are persistent, with the natural result of gaps twice as numerous as the appendages. Fig. 66 shows part of the foregoing much more highly magnified. At the top is a persistent leaf and in the middle line below lies the pith, which is sending off an extension, the leaf gap; and this, on reaching the second annual ring, undergoes considerable enlargement. Between the wide termination of the leaf gap in the beginning of the second annual ring and in line with and subtending the leaf on the outside of the stem lies the foliar ray. The magnification is not sufficient in the figure to show the organization of the leaf ray; hence a more enlarged representation is introduced in Fig. 67. Here it is clear. FIG. 66.—Part of transverse section of a twig of Casuarina Fraseri more highly 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 Jeffrey, Edward C. (Edward Charles), b. 1866. Chicago, Ill. , The University of Chicago Pr
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