fase OED OGON DA CEA E 19 
-and variously anastomosate. The color of the oospore changes 
with age from green to brown (or yellowish-brown) or red. 
The oospore upon liberation from the rest of the filament by 
disintegration of the vegetative and oogonial cells sinks to the 
bottom of the pond or other body of water, or lodges on peren- 
nial aquatic macrophytes, or as in the terrestrial species of 
Oedocladium lies in the damp earth. After a period of rather 
prolonged dormancy, which apparently may vary from a few 
months to a few years, it begins to grow. Although the data 
have been secured for a few species only, it is the usual occur- 
rence for the contents of the oospore to divide and form four 
zoospores at germination (Pl. X, figs. 78-83; Pl. LXIV, figs. 
646-647). Upon their liberation from the old oospore wall, 
the zoospores swim about for a time, come to rest, and germ- 
inate into new filaments, precisely in the same manner as those 
produced directly from the vegetative cell. The reserve food 
in the oospore is a fatty oil dissolved in a reddish-brown 
pigment. The oospore is considered the diploid structure in 
the life history, the remainder of the plant being haploid. 
The antheridium of the monoecious and dioecious-mac- 
randrous species is derived from the division of a vegetative 
cell, the cross wall arising near the upper part of the cell. If 
no more divisions occur, we have a single antheridium, often 
designated as unicellular (Pl. XIV, fig. 136). Subsequent 
divisions result in a series of antheridia (2 to 45), termed 
multicellular (Pl. XIII, fig. 125). In the monoecious species 
the antheridia may be near the oogonium (epigynous, sub- 
epignous, hypogynous, etc.) or scattered at some distance from 
the oogonium (Pl. XV). In the dioecious-macrandrous species 
the occurrence of seriate antheridia often results in considerable 
distortion of the filament, particularly if apically located (PI. 
XVI, fig. 153). In Bulbochaete the antheridium may arise 
(as in the development of the oogonium) by a horizontal 
division of the vegetative cell, resulting in an erect antheridium 
(Pl. 1X); if the division is oblique, the antheridium is part of a 
side branch terminated by a bristle: a patent antheridium 
(Pl. IX). Antheridia of Oedocladium usually occur on special 
branches, formed as in Oedogonium. 
The contents of each antheridium produces one sperm, or 
as in most species, two sperms. The division of the antheridium 
when two sperms are formed is either horizontal, one lying 
superimposed on the other (Pl. XV, fig. 145); or vertical, the 
