52 THE PALM-STEM: 



Pre-eminently deserving of mention is the acute Essay 

 of Meneghini (Ricerche sulla Struttura del Caule nelle 

 Piante Monocotiledoni, Padova, 1836), in which the 

 structure of the stem of Monocotyledons is traced in its 

 various forms, and described with great clearness. So 

 far as this exposition relates to the arborescent Monoco- 

 tyledons, the following points might indeed be brought 

 forward in opposition to my description. Meneghini, 

 who, in his description of the course of the vascular bundle, 

 traces it as I did from above downwards, devotes especial 

 attention to the changes which its position undergoes 

 during the development of the terminal bud into stem, 

 and, in reference to this, lays particular stress upon the 

 circumstance that, so long as the leaves remain inclosed 

 in the bud, only that part of the vascular bundle exists, 

 which in the full-grown bundle runs from the middle 

 of the stem downwards and outwards, and that its upper 

 portion is first developed with the development of the bud 

 into stem, and with the emergence of the leaves from the 

 centre of the bud out to the lateral surface of the stem. 

 From this passage outward of the leaf from the centre of 

 the bud, is derived the curve of the vascular bundle in the 

 centre of the stem, and the outward direction of the course 

 of the upper part of the vascular bundle. Meneghini paid 

 especial attention to the examination of the circumstance 

 that the vascular bundles present, not only this curve out- 

 ward, but at the same time a lateral bend, so that their 

 lower extremity does not lie in a perpendicular direction be- 

 neath the upper end, but diverges to its left or right. I also 

 had observed this circumstance in the Palm- stems I inves- 

 tigated, but attached no importance to it, as I considered 

 the oblique course of the fibres an accidental deviation. 



examination of such works as have had an influence on the progress of the 

 study of the structure of the stem of Monocotyledons, and especially of the 

 Palms, whether by the announcement of new, hitherto unnoticed facts, or by 

 the extension of the study in its theoretical aspect ; I therefore shall pass 

 over, in particular, Gaudichaud's works, since the researches on which his 

 theory rests, have too much the stamp of superficiality to allow me to expect 

 any profit from them to the study of the structure of plants. 



