526 A BOTANICAL EXCURSION IN MY OFFICE. 
from the position of the cilia (Fig. 2) there grow, during 
this process of germination, little root-like processes 
which attach themselves to some anchorage, but I have 
not been able to detect them in the aquarial inhabitant. 
The cell, having acquired a wall, and thus perfected 
itself, now begins to elongate; by and by it undergoes 
cell division, and thus divides itself in its length into two 
cells, which grow and divide, and by repetitions of this 
process, the filament is formed, that which we noticed at 
first. This plant belongs to the genus G/dogonium, the 
species of which are arrangeable into three sets; first, 
those in which the single filament produces both male and 
female organs; secondly, those in which male and female 
organs are produced in distinct filaments; thirdly, those 
in which the female filaments produce, besides the regu- 
lar zoéspores, others which, in germinating, grow into 
peculiar dwarf plants, in which are formed “the male 
germs. These three sets are known respectively as mo- 
neecious, dicecious, and gynandrosporous plants ; the term 
androspore being given to the zodspore, whose function is 
to grow into the little dwarf male plant. The Œdogo- 
nium of the aquarium belongs to the gynandrosporous 
division. 
Besides these zodspores the CEdogonia produce, by means 
_ of a specialized reproductive system just alluded to, a spore 
or seed which is known as a resting spore. In our plant 
this is produced as follows: a cell in the main filament 
begins to enlarge, and, at the same time, a communica- 
tion is opened between it and the next proximal cell, 
whose endochrome is emptied into it. The two consoli- 
dated endochromes now contract themselves into a round- 
ish ball in the swollen cell, the sporangia or spore-case- 
About this time hrast of the poves (Fig. 3) attach 
