APPENDIX. 77 



base of the stem, is incorrect as regards the Palms. I 

 was led to the assumption by the investigation of too 

 young specimens (for I only had such in an entire con- 

 dition, and the portions of full-grown Palm-stems at my 

 disposal were merely short pieces), as well as by too wide 

 an extension of the analogy with the stems of Draccena, 

 Yucca, &c. The grounds on which I now hold the view 

 that the fibres run down to the base of the full-grown 

 stem is false, are anatomical. It is clear, that in the 

 transverse section of an old Palm-stem, we ought to find 

 beneath the rind the fibres which are only just beginning 

 to be formed, as Moldenhawer states that he did, although 

 he had indeed no large stems to investigate ; now in the 

 examination of sections of old stems I have not seen 

 this, but all the fibres lying beneath the rind were com- 

 posed of thick-walled cells, consequently were old. A 

 subsequent growth of the fibres beneath the rind of full- 

 grown stems, therefore, does not take place. The matter 

 is altogether different in respect to the stems of Aletris, 

 Dracana, &c. ; here there is a layer beneath the rind 

 perfectly comparable with the cambium-layer of the 

 Dicotyledons, in which parenchymatous cells and fibrous 

 bundles grow subsequently, which formation of new 

 structures gives rise to continual increase of thickness of 

 these stems. It is proved by this that the fibres termi- 

 nate higher up in the stem in the Palms, and that in 

 them must exist a condition similar to that in many 

 Dicotyledons, where the vascular bundle can only be 

 traced down through a certain number of internodes. 



Passing now to the most important part of Mirbel's 

 treatise, the examination of the terminal bud, he states 

 that he found two slits, one above the other, in the centre 

 of the flattened, concave, excavated apex of the stem, 

 composed of nascent cellular tissue (to which he applies 

 the name of pfiyllopliore], these slits dividing the cellular 

 tissue into superimposed layers. Of these layers each, 

 according to his views, represents a nascent leaf; the 

 upper one is elevated into a vesicle, and this becomes 



