THE ANGIOSPERMS 97 
other materials which are in solution, to the stem of the 
plant. 
2. The stem.—Cut across the stem and with the hand 
lens or low power of the microscope note the bundles of 
tissue mentioned above. Make a diagram showing how they 
are arranged in the cross-section of the stem. Usually 
there will be seen some of the very large cells of the pith 
tissue among the bundles, while around all of this is the 
bark tissue. 
3. The leaf—a. Draw a leaf showing (1) its attach- 
ment to the stem; (2) its form, whether the margin is 
notched ; (3) its system of veining—how the veins branch, 
their relative size, and how they terminate. These veins 
are continuations of the fibrous bundles from the roots 
and stem. 
b. Carefully peel off a little of the epidermis from both 
surfaces of the leaf, mount with the outside up, and study 
the general form of the epidermal cells and the stomata. 
Each stoma consists of two guard-cells and an opening, the 
outer part of which may be seen between the guard-cells. 
Draw. 
The stomata assist in regulating the amount of water 
in the leaf, and may also serve to transmit gases to and 
from the leaf. 
c. Make a thin cross-section of the leaf, mount, and ex- 
amine, noting (1) the epidermis on upper and lower sides ; 
(2) the chlorophyll-bearing tissue, that which is near the 
upper epidermis, because of its arrangement and form, be- 
ing known as palisade tissue, and that below as spongy 
tissue; (3) the cross-sections of veins; (4) the stomata, 
usually in the lower epidermis. Draw. What part of the 
leaf does most chlorophyll work? What part is best 
adapted to the transportation of materials? 
Reproduction The flower—When all the floral leaves 
are alike in color they are designated by the term perianth. 
