FRESH-WATER ALG. 219 
from the yob5th to the syyoth part of an inch in 
diameter. Each of these cells has an opening 
surrounded by serrated or indented lines, whose 
smallest diameter measures only the sgooth part 
of an inch. It encloses nitrogenous contents, is 
tinged with chlorophyll, and contains starch. The 
plant, when perfect, bears no inapt resemblance 
to a red-currant berry ; as it decays, the red col- 
ouring matter gradually fades into a deep orange, 
which finally appears to change into a brown hue. 
The thickness of the wall of the cell does not ex- 
ceed the sygpoth part of an inch. Each one of the 
cells may be regarded as a distinct individual 
plant, since it is perfectly independent of others 
with which it may be aggregated, and performs 
for and by itself all the functions of growth and re- 
production ; having a containing membrane which 
absorbs liquids and gases from the surrounding 
matrix or elements, a contained fluid of peculiar 
character formed out of these materials, and a 
number of excessively minute granules equivalent 
to spores, or, as some would say, to cellular buds, 
which are to become the germs of new plants. 
There is something extremely mysterious in the 
performance of these widely different functions, 
by an organism which appears so excessively 
simple. That one and the same primitive cell 
should thus minister equally to absorption, nutri- 
