

42 - FLOWERING PLANTS 
portion, the nucleus, and colouring matter not uniformly 
distributed, but confined to certain 
definite portions of the protoplasm. 
The nucleus is best seen by staining | 
the cell with iodine (Appendix 4A). 
The result of staining is that the 
cell-contents get brown, the chloro- 
phyll bodies losing their green colour 
and becoming brown, whilst the 
ae nucleus gets a deep brown. After a 
Fic. 6.—Restine Pro- little time, if enough iodine has been 
TOCOCEUS. “added, the protoplasm shrinks away 
Hehe | aaa from the cell-wall, which is then very 
c.w, cell-wall. clearly seen. 
- oe Tie remaining portions of the 
cell, not filled with protoplasm but with cell-sap, are called 
vacuoles (Lat. vacuus, empty). The cell-sap also saturates the 
whole cell. 
Kach Protococcus cell, whether motile or stationary, is a 
living organism, able to perform all the functions essential to 
lite (“Elementary Botany,” pp. 111-114). The simplest forms . 
of plant-life consist of living masses of protoplasm, each 
similar in its essential nature to that of Protococcus, and— 
either naked or enclosed in a common cell- wall. Vaucherta 
is a type of the latter. 
This Alga is often found growing like a green 
felt on the soil in pots in greenhouses, and is of | 
a dull green appearance. 
Vaucheria consists of very many masses of protoplasm 
enclosed in a common wall. It cannot be described as a 
unicellular plant, for many nuclei are present in its proto- 
plasm, although they are unevenly distributed. At the same 
time, it would be incorrect to apply the term “ multicellular ” 
to it, for usually there are no cell-walls separating the various 
masses of nucleated protoplasm from each other. An organism 
of this kind is termed a Cenocyte (Gk. koinos, common, kutos, 
a cell or vessel). 

Vaucheria. 
