484 LIFE-HISTORIES 
The smaller motile protoplast is plainly the male gamete, and 
the larger, non-motile one, the female. Hence the cells in which 
they arise may be called respectively the male and the female 
gametangia,' the cells in which non-sexual spores appear, being 
termed sporangia.2. Union of a male with a female gamete is dis- 
tinguished as fertilization. As a result of this process in Coleochete 
the fertilized gamete, still remaining within the gametangium, en- 
larges, and incloses itself in a new cell-wall, thus forming what is 
called an odspore,* which becomes further protected by an envelope 
of branches (r, Fig. 315 B); for a cell at its base is stimulated to 
Fig. 315.—Cushion Sheath-alga (Coleochete pulvinata, Sheath-alga Family, 
Coleochetacee). A, part of a thallus bearing male (an) and female 
(og, og’’) gametangia; and bristle-like projections sheathed at the 
base (h, h); male gametes, 2, 2, 292. B, ripe odspore in its rind (7). 
C, odspore germinating by the formation of swarm-spores (sch). 
D, swarm-spores of different ages. B-D, 24%. (Pringsheim.)— 
Found with the other species, forming small cushions. 
produce several new cells, which, growing up around the game- 
tangium-base and oospore produce a sort of rind. Thus protected 
the odspore rests through the winter. In spring the protoplast, by 
division of its nucleus and the formation of partitions, is transformed 
into a little mass of cells firmly united with one another but quite 
distinct from the old cells surrounding them. In this little mass 
we have, in fact, a new plant entirely different from the sexual 
plant which produced it. It never produces gametes, but from each 
cell comes a single swarm-spore which under favorable conditions 
1 Gam’’e-tan’gi-um < Gr. angeion, a vessel. 
2 Spor-an’gi-um < Gr. spora, spore. 
3 O’o-spore < Gr. oon, an egg. 
