84 



ORGANOGBAPHT. 



case with the bark of Exogenous plants, but it is formed by the 

 ends of the vascular bundles, as will be presently noticed, and 

 cannot therefore be separated from the mass beneath. 



Fig. 170. 



F!a. 170. 1. FnbrancBed stem of the Cocoa-nut Palm (Cocos nucifera). 2. 

 Branched stem of Pandanus odoratii>simus. The figures are placed at 

 the base to indicate the height. From Jussieu 



In annual or herbaceous endogenous stems the parenchyma 

 between the vascular bundles is soft and delicate, but in trees 

 which grow to any height, as Palms, the cells become hardened 

 by the deposition of secondary layers, and thus form what has 

 been termed woody farenchyma, which ultimately binds the 

 original separate bundles into a solid hardened mass resembling 

 wood. 



The structure of the vascular bundles thus distributed in the 

 parenchymatous system has been already referred to under the 



