140 PHARMACEUTICAL BOTANY 
serve as storage places for starch, alkaloids, resins, and other 
substances. (Cf. Figs. 62, 127, 139.) 
VASCULAR AND FIBROVASCULAR BUNDLES 
VASCULAR BuNDLEs are strands of conducting elements con- 
sisting of elongated cells specialized for the conduction of sap. 
The conducting strands are of two kinds: the PHtozm which 
carries elaborated food materials (e/aborated sap) from the leaves 
and green parts of stems to all parts of the plant, and the XyLem 
which carries soil water with dissolved mineral salts (crude sap) 
from the roots to the leaves. 
Tracheal tube carrying food upward Sieve tube carrying food 
downwards from 
Kylem parenchyma recéiving 3] Chk eaves 
P food from medullary rays } 
> i “i\ and storing it if 
2° p Lea? 4 2 09 \* el *%e? 
id Ay *? 99 0\0% "| « 
es yout \\e 47% Cambium { m5 oe. 
oho (9¢ Sy "OO | ile@s oA 
a Soe A ae hie Hie ee 
Saare- em ae rarer — agaee oo oo = > ~ 3 é < 
[40 9 eS Sloeee Va \\ ly de o,° ee 
vo 
f Parenchyma 
Medullary ray cells carrying food inward and outward storing food 
from the sieve tubes The ray cells also store food 
Fic. 78.—Diagram showing the transport of food through the sieve tubes, 
medullary-rays and tracheal tubes (trachez), and its storage in the parenchyma 
cells of the wood and bark. The black bodies in the cells indicate stored food. 
(Stevens.) 
FIBROVASCULAR BUNDLES are groups of fibers, vessels and cells 
coursing through the various organs of a plant and serving for 
conduction and support. The term “Vascular Bundle’ is 
employed to indicate bundles whose xylem and phloem contain 
no fibers and which are devoid of enveloping fibrous sheaths. 
According to the relative structural arrangement of their xylem 
and phloem masses, they may be classed as follows: 
I. Collateral, consisting of a xylem and a phloem strand 
extending side by side. 
II. Closed collateral, consisting of a strand of xylem lying 
alongside of a strand of phloem, in intimate contact, with no 
cambium zone between them. Stems and leaves of most Mono- 
cotyledons and Horsetails. 
III. Open collateral, consisting of a strand of xylem and a 
strand of phloem separated from each other by a cambium. 
