20 Me (OVE DOGO AGE Aw 
sperms lying side by side (Pl. XX, fig. 182). In the dwarf 
males the division is always horizontal. The sperms look lke 
small zoospores and are liberated in the same manner from the 
filament. After swimming actively for some time, the sperm 
enters the opening of the oogonium with subsequent fertilization 
of the egg and production of the oospore. 
The formation of the antheridia in the dioecious-nannandrous 
species involves the production of androsporangia, the develop- 
ment of which is practically identical with that of the anther- 
idia. The androsporangia may be developed singly or seriately 
(Pl. V, fig. 37; Pl. LV, fig: 528; Pl. XLVwiie. 484). “Phe entire 
contents of the androsporangium produces a single androspore 
(Pl. LXII, fig. 606), a spore that superficially resembles a sperm 
or zoospore in form, in manner of liberation from its sporangium 
(androsporangium), and in activity. Upon coming to rest, 
however, it germinates and produces a short filament known 
as the dwarf male, or nannandrium (Pl. LXIV, fig. 645D). 
This germination of the androspore occurs on the oogonium or 
suffultory cell, or rarely on scattered vegetative cells. 
Division of the germinated androspore results in a lower 
non-reproductive stipe (holdfast cell) and an upper small 
cell, the antheridium (Pl. XLVI, fig. 448 A and S). Subsequent 
divisions of either stipe or antheridium produce additional 
antheridia (2 to 4) (Pl. XLVI, fig. 448). If merely an inner 
partition is formed, the antheridium is zuternal and single 
(Pl. LI, fig. 486); if the customary ring-formation takes place, 
the antheridium is termed external (Pl. LX, fig. 584). The 
dwarf males are rarely unicellular (Pl. LIII, fig. 505), and the 
stipe, though usually one-celled, may be few-celled (Pl. XLVI, 
fig. 459). Two sperms are normally formed in each antheridium 
by a transverse division of its contents. The basal cell of the 
dwarf male, formed as noted above, is usually an elongated, 
either simple or slightly lobed holdfast. 
The basal cell of the filament, resulting as noted previously 
from the germinating zoospore, is most frequently elongated 
(Pl. LXIV, fig. 637). The attached lower end may be simple 
or much lobed. In some species the developing basal cell may 
be flattened into a subhemispherical cell or rarely appear 
nearly spherical (Pl. LXIV, fig. 636). The smaller species 
remain attached throughout almost their entire life history. 
The larger ones usually become detached and sometimes are 
