102 PRACTICAL COURSE IN BOTANY 
the cell wall by osmosis? [56 (4).] The 
conducting cells are surrounded by a mass 
of strengthening fibers separating them 
from the parenchyma, f, and constituting 
with them a fibrovascular bundle. The 
| larger vessels, m, m', a, and sp, compose 
Nein ‘| the aylem, the harder, more woody part 
cy lof the bundle, and the smaller ones, », s, 
the phloém, or softer part. Notice also 
that there is no parenchyma in contact 
with the xylem and phloém in the fibro- 
vascular bundles of a monocotyl, to supply 
; material for new growth, but they are 
seer oes entirely surrounded by a sheath of strength- 
tube of a gourd stem: ening tissue, whence such bundles are said 
i oe aa he closed, and are incapable of farther 
fee Elgar muci- growth by the addition of new cells. 
B. Herpaczeous Dicoryis 
MareriaL. — Young stems of sunflower, hollyhock, burdock, ragweed, 
cocklebur, castor bean, or any large herbaceous plant. In schools un- 
provided with compound microscopes, the minute anatomy can be studied 
with some degree of profit by the aid of pictures. 
115. Gross anatomy. — Examine the outside of a young 
stem of sunflower, burdock, or other herbaceous dicotyl. 
Notice whether it is smooth, or roughened with hairs, scales, 
ridges, or grooves. If hairy, observe the nature of the hairs, 
whether bristly, downy, sticky, ete. Notice the color of the 
epidermis, whether uniform, or splotched or striped with 
other colors, as, for example, jimson weed, and pigweed 
(amarantus). If there are any buds, branches, or flower 
stems, notice where they originate; what is the angle be- 
tween the leaf and stem called? (100.) 
Make a transverse cut through a portion of the stem that 
has stood for a time in coloring fluid and examine with a lens. 
Four regions can easily be distinguished: (1) the epidermis,. 
