CHAPTER I 
THE CELL 
The cell is the unit of structure of all plants. In fact the 
cell is the plant in many of the lower forms—so called unicellular 
plants. All plants, then, consist of one or more cells. 
While cells vary greatly in size, form, color, contents, and 
function, still in certain respects their structure is identical. 
TYPICAL CELL 
The typical vegetable cell is composed of a living portion or 
protoplast and an external covering, or wall. The protoplast in- 
cludes everything within the wall. It is made up of a number 
of parts, each part performing certain functions yet harmonizing 
with the work of the cell as a whole. The protoplast (proto- 
plasm) is a viscid substance resembling the white of an egg. 
The protoplast, when unstained and unmagnified, appears 
structureless, but when stained with dyes and magnified, it is 
found to be highly organized. The two most striking parts of 
the protoplast are the cytoplasm and the nucleus. The part 
of the protoplast lining the innermost part of the wall is the 
ectoplast, which is less granular and slightly denser than most 
of the cytoplasm. The cytoplasm is decidedly granular in 
structure. 
In the cytoplasm occurs one or more cavities, vacuoles, filled 
with cell sap. Embedded in the cytoplasm are numerous 
chromatophores, which vary in color in the different cells, from 
colorless to yellow, to red, and to green. The nucleus is the 
seat of the vital activity of the cell, and the seat of heredity. 
The whole life and activity of the cell centre, therefore, in and 
about the nucleus. 
The outer portion of the nucelus consists of a thin membrane 
or wall. The membrane encloses numerous granular particles— 
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