Page:The Oak.djvu/68

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50
THE OAK.

The veins which spring from the chief lateral ribs run towards one another and anastomose, giving off smaller veins which form a network in the area included by them. In the neighborhood of the leaf-margin, however, the smaller veins curve towards one another, and make arches convex towards the margin. In the finer meshes individual minute branches run to the center of a mesh and end there. Round the extreme edge of the leaf is a single vascular bundle; this receives small bundles from the above-mentioned arches, and also receives the ends of the midrib and the chief lateral ribs (cf. Fig. 1).

The vascular bundles of the axillary bud, which will eventually, of course, form a system like that already described on their own account, pass down and join the bundles of the parent axis as follows:

The bundles of each lateral half of the bud (Fig. 11, a a) pass down together between the bundles of the leaf-trace of the leaf from whose axil the bud arises, and the next lateral bundles of the stem with which the leaf-trace bundles are conjoined; the common strand formed by the bundles of each side of the bud then joins with a bundle coming down from another leaf. A few of the strands may also join to the bundles of the leaf-trace itself.

At the back or top side of the bud—i.e., the side next the stem which bears it—a few vascular bundles pass from the bud to the nearest strand (Fig. 11, z) this is the middle strand coming down from the leaf