316 
PHYSIOLOGY. 
BOOK II. 
branches crossing each other or lying parallel, after the 
manner of the ordinary ligneous tissue of a Palm stem 
191 192 
193 
[Jig, 193.), only the bundles do not adhere to each other, 
and are not embodied, as usual, in a cellular substance. These 
bundles may be readily traced to the central column, parti- 
cularly in the younger branches [Jig, 191.), and are plainly 
the roots of the stem, of exactly the same nature as those 
aerial roots which serve to stay the stem of a Screw Pine 
(Pandanus). When they reach the earth, the w’oody bundles 
become more apparently roots, divided at their points into 
fine segments, and entirely resembling on a small scale the 
roots of a Palm-tree. The central column is much smaller 
