THE PALM-STEM. 17 



centre, and from this again outwards to the periphery, 

 it is clear that in every transverse section of the stem we 

 must meet with the fibrous inferior extremities of the 

 vascular bundles at the periphery ; further in, the thick 

 and hard part of the bundles formed further up ; and 

 toward the middle of the stem, the soft part of the 

 bundles in the situation of their more vertical course 

 beneath their point of curvature ; finally, we may meet 

 with the portion of the bundles, in which they run from 

 the centre toward the leaves, in the most varied situations, 

 among the others. The last vascular bundles will be cut 

 through more or less obliquely, the rest in pretty nearly 

 a fair transverse section. 



The examination of such a transverse section by the 

 microscope, shows that the outer fibrous bundles are 

 composed solely of thick-walled prosenchymatous cells, 

 which correspond to the liber-cells of the other vascular 

 bundles. More toward the interior, we meet with large 

 bundles, which already exhibit the perfect composition of 

 the vascular bundle ; they are distinguished by their liber- 

 mass being relatively very large, and by having the wood 

 consisting of a single vessel surrounded by but few cells. 

 The proper vessels likewise exist only in small numbers. 

 Further inward, where the vascular bundles have attained 

 their most considerable size, they are composed in greatest 

 part of thick-walled, lighter or darker brown cells, the 

 wood is still but slightly developed, yet contains already 

 one or two vessels of tolerable size, which are inclosed 

 by few, somewhat thick -walled, cells ; the proper vessels 

 are also but little developed, and are readily distinguished 

 from the wood-cells by their thinner walls. Still further 

 inward, in the transition to the soft part of the stem, the size 

 of the vascular bundles diminishes ; they exhibit a rounder 

 form, since the liber-mass is considerably smaller and 

 assumes the form of a crescent, in the concavity of which 

 the proper vessels are received, and behind these lies the 

 strongly developed woody portion. In this occur one or 

 two large vessels, with several smaller behind them. The 



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