38 LEAVES 
the leaf one or more than one cell thick? This can be 
ascertained by changing the focus of the microscope. 
Draw three cells in each of the three regions above men- 
tioned and fill in one. . 
The chloroplasts are imbedded in protoplasm. Some 
of them will be found to be in motion. In which cells do 
they move fastest? Do they move thru the protoplasm 
or are they carried by it? Do they pass thru the walls 
from one cell into another? Is the direction of motion 
the same in all cells? Add one drop of 20 per cent. salt 
or sugar solution to one edge of the cover glass and 
slowly draw it under by means of a piece of blotting 
paper held at the opposite edge. After the cells in 
the leaf are slightly plasmolyzed replace the solu- 
tion with water. Result; conclusion? Ask the instructor 
for alcohol containing Elodea leaves. Study one of the 
leaves under the microscope. What change did the alco- 
hol produce in the leaf; in the chloroplasts? Compare 
the alcohol with fresh alcohol and note the difference in 
color. Conclusion? Wha* is the green color in leaves 
due to? 
Literature. 
Bergen: Foundations of Botany...... 0.2.60 32. ee 178-185 
Bergen:  Mlements ot Botany) soe enc ole ee Lee ee 126-130 
Leavitt: Outlines of Botany.............. ie esas ee ee 212-215 
pievens: Introduction to: Botany. ... 03.050 ee 104-110 
maimes: Plant Life soit 6 be eb Sh eee 1-7 
