The Anatomy and Morphology of the Leaves and Inflorescences of Welwitschia mirabilis . undles of the groups are alone concerned inthe production of lateral traces. For some time the same corner bundle may run onin the axis, supplying traces to bracts and flowers. Sooner or later it becomes usedup in this process, and passes out entire. This occurred at the fifth whorl of flowersin one cone which was examined, and was seen to happen at intervals in all fourgroups. Its place is then supplied in the cone-axis, and the normal number ofbundles restored, by the branching of one of the others, a new
The Anatomy and Morphology of the Leaves and Inflorescences of Welwitschia mirabilis . undles of the groups are alone concerned inthe production of lateral traces. For some time the same corner bundle may run onin the axis, supplying traces to bracts and flowers. Sooner or later it becomes usedup in this process, and passes out entire. This occurred at the fifth whorl of flowersin one cone which was examined, and was seen to happen at intervals in all fourgroups. Its place is then supplied in the cone-axis, and the normal number ofbundles restored, by the branching of one of the others, a new corner bundle beingthus formed, which now takes part in the supply of bracts and flowers (Dia. III).Thus, in turn, each of the bundles in the cone-axis takes part in the formation offoliar and flower traces, and none of them is entirely cauline. * Strasburger, 1872, p. 146, remarks on these two bundles and suggests that they have the appearanceof being about to supply a pair of foliar segments,t Strasburger, 1872, pp. 144-145. LEAVES AND INFLORESCENCES OF WELWITSCHIA MIRABILIS. 191. DiA. Ill illustrates the course of one of the four groups of vascular bundles in the base of the axis of a malecone. It is constructed from a series of transverse sections. I, II, III, the three bundles of a bract traces (Bi-Bs) and three flower traces (Fi-Fs) are formed in the normal manner. Eachflower trace is joined by a small trace from the corner bundle of the next group. The bundles I andIII are used up in the formation of the fourth flower and bract traces. Bundle II then branches tofill their places. D. Naked Inflorescence Axis (Male), The naked axis has an epidermis which is sHghtly cuticularised, and in whichstomata are sparsely distributed, occurring chiefly just beneath the bracts at thepoints of forking. The cortex is composed of thin-walled cells, interspersed withnumerous groups of sclerenchymatous fibres; below the bracts occur lignifiedbranching fibres and mucilage-conta
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectproceed, bookyear1911
