330 A TEXTBOOK OF GENERAL BOTANY 
Relationship. The Charales are generally considered as hav- 
ing been derived from green alge, but they are so very different 
from the remainder of the green alge that they are frequently, 
if not usually, placed 
in a separate class. 
VAUCHERIA 
Structure. Vaucheria 
is a representative of the 
order Siphonales, which 
is characterized by the 
fact that the vegetative 
(nonreproductive) por- 
tion of the plant consists 
of branching filaments 
with many nuclei but no 
cross walls. Cross walls 
normally occur only in 
connection with the re- 
productive organs. 
Vaucheria is found 
in water and in damp 
places. A plant consists 

Fre. 338. Stages in the germination of 
Characeae 
The two on the left redrawn after De Bary; the ‘ 
one on the right redrawn after Pringsheim of a sparing ly branched 
filament, in the vegeta- 
tive portion of which there are no cross walls. The cell wall is 
lined with protoplasm, while a vacuole extends through the cen- 
ter of the filaments. Numerous nuclei and chloroplastids occur 
in the protoplasm. The plant is attached to the substratum by 
a colorless branched filament, the holdfast. 
Reproduction. Vaucheria reproduces asexually by the pro- 
duction of compound zodspores. The end of a filament enlarges 
and is cut off from the remainder by a cell wall. The contents 
are then transformed into a large oval zodspore (Fig. 840). This 
contains many nuclei and has numerous cilia, which occur in 
pairs, each pair being opposite a nucleus. Since each pair of 
