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THE PALM-STEM :

ance in their original formation. A vascular bundlewhich runs from the summit of the petiole of such a half-developed leaf, through the petiole and bud, to the outersurface of a part of the stem situated far lower down,may, according to what has just been said, exhibit itscomplete development and solidity at both ends, whichlie in organs already completed and solidified, while itsmiddle portion, in its course through the lower part ofthe petiole and through the upper soft portion of the stem(the phyllophore) concealed in the bud, is gelatinouslysoft, and, in reference to the anatomical completion of itsindividual elementary organs, still in a young condition.In the same proportion as these soft parts advance indevelopment, as the part of the phyllophore through whichthe vascular bundle runs becomes part of the stem, andthe petiole and leaf-sheath attain their full size and be-come solidified, will the soft part of the vascular bundlealso increase in size and internal completeness, till itsgrowth is finally terminated, and it is solidified. This,and nothing further, do we learn from a view of thesection of a bud, and when Mirbel finds in the increaseof solidity which the vascular bundles exhibit from abovedownwards, a proof of the direction in which they origi-nate, the validity of this conclusion must be altogethercontested.

The question, in which direction the vascular bundlesare formed at their first origin, can only be decided bydirect observation of the process of their origination;therefore, only by microscopic investigation. Mirbel didnot neglect researches of this kind, and he states, that hesometimes caught the vascular bundles at the momentwhen they were betaking themselves into the rudimentaryindications of the leaves. In the examination of the ter-minal buds of various Monocotyledons, especially in Iris ,Acorus Calamus, of the bulbs of Narcissuspoeticus, I cameto the result, that the first indications of,the vascularbundles, in the form of transparent streaks, are to bemet with beneath the youngest leaves, in the axial portion