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THE PALM-STEM :

torn away, in a circular direction in the greatest part ofits circumference. The isthmus is developed into thepetiole, the upper part of the vesicle becomes erected,acquires the shape of a spoon, and is converted into theleaf, the vagina of the leaf appears to grow out from thewound which the torn leaf leaves upon the phyllophore.The leaf acquires the form of a hood, its border havingan irregular thickening; the two lateral halves of the hoodare formed of the two series of leaflets, and the thickenededge, which unites the points of the leaflets, subsequentlybecomes absorbed.

The description of this process does not agree in theleast with what I observed in regard to the earliest periodof the formation of the Palm leaf. I examined, in referenceto these statements of Mirbel, the terminal buds ofPhoenix and Cocos jlexuosa , but found, as in other Mono-cotyledons, such as Agave, Yucca, no trace of origin ofthe leaf under the form of a circularly torn vesicle as de-scribed by Mirbel, but saw the leaves shoot forth fromthe axis in the form of obtuse papillae. This papilla is atfirst narrow, in proportion to the portion of the axis onwhich it stands, since the first-formed part of it corre-sponds to the apex of the future leaf; the further it isdeveloped, the more the base rises from the surface of thestem, so that in the Palms an indication of the vagina ofthe leaf is visible at a very early period. I cannot under-stand how Mirbel came to the idea that the leaf originatesin the form of a vesicle, and that several such vesicles lieone above another ; he must have been led to this view bya longitudinal section which did not pass exactly throughthe axis of the bud, and thus have met with sheaths ofyoung leaflets (which in the inner parts of the bud are notcylindrical, but have the lower part spread out almost flat),and have taken them for the rudiments of the whole leaves.I deduce another reason against the assumption that theleaflets originate from closed vesicles, from the observationof a monstrous formation which I found in a branch ofPhcenix, the axis of which had grown out to the length