THE PALM-STEM. 9 



The vascular bundles of the Cocos- and Calamus-like 

 stems are distinguished by their not exhibiting that her- 

 baceous softness in their course from the leaf to the 

 centre, and from this to the outer layer of the stem, for 

 they also appear thick and woody here, although in a less 

 degree than in the outer layers. With regard to the 

 inferior portion of the vascular bundle, two varieties are 

 met with in the Cocos-like stem : it either passes, as in 

 Kunthia, into a thin fibre, and the external fibrous layer of 

 the stem is then thin, as in the rest of the forms, or the 

 vascular bundle divides, at its exit from the hard layer, 

 into several smaller bundles, which, after a short course, 

 lose themselves in a multitude of fine fibres ; the fibrous 

 layer is then thick, as, for instance, in Cocos nucifera, 

 coronata, &c. 



From this course of the vascular bundle is deduced 

 the following statement : The doctrine laid doivn by 

 DESFONTAINES, that the new vascular bundles originate in 

 the centre of the stem, and that the harder and thicker 

 vascular bundles., situated at the periphery of the stem, are 

 older than the soft ones occupying the centre, and that, 

 therefore, the vegetation of Monocotyledons is wholly 

 different from that of Dicotyledons, is altogether incorrect 

 and inadmissible. 



Obs. 1. From the circumstance that the vascular bundles run from the 

 leaves to the middle of the stem in a curve of small radius, but that from 

 here, in their way downward, they only approach the rind gradually, we can 

 understand how phytotomists have been led to assume that they originate in 

 the middle of the stem. Indeed, this outward course is not easily observed 

 in a stem split longitudinally, unless the single vascular bundle is dissected 

 out. One circumstance, however, must have long since indicated the incor- 

 rectness of Desfoutaines' doctrine. If, namely, the vascular bundles of the 

 younger leaves lay more internally in the stem than those which go to the 

 older leaves, the former could never cross the latter. Now, it is easily 

 seen in all Palms, that the vascular bundles entering a leaf, cross those which 

 run to the leaves situated higher up, which is only possible by the arrange- 

 ment of the fibres described above. This crossing is the more striking the 

 thicker the stem and the closer its leaves, therefore much more evident in 

 the species of Cocos than in Kunthia ; it is still more distinct in Xanthorrhoea 

 hastilis (vide De Candolle, Organogr. tab. 7, 8), in a transverse section of 



