420 BRYOPHYTES (MOSS PLANTS) 
plants of some Mosses can be identified by a small terminal cup 
in which the antheridia are produced. 
The antheridia produce numerous swimming sperms, and, when 
there is suitable moisture, the sperms reach the archegonia, swim 
down the long necks into the venters, and fertilize the eggs. 
The fertilized egg begins to grow almost immediately after fer- 
tilization, and like the fertilized egg of the Liverworts, it develops 
in the place in which it was formed. By rapid growth and cell 
division, it soon forms a spindle-shaped body with one end called 
foot pushing into the stem of the gametophyte to absorb food, 
Fic. 375.— A protonema of Moss (X 50). Buds which develop leafy 
gametophores are shown at b. 
and the other end pushing into the air, forming a stalk called seta 
which bears a sporangium at its upper end in which the spores 
are produced. As the sporophyte develops, the venter about the 
young sporophyte and also the neck of the archegonium enlarge. 
Finally the venter is ruptured and the enlarged archegonium is 
carried up by the sporophyte, forming a pointed cap on the top 
of the sporangium. When the spores are shed and fall on a 
moist soil, they produce new gametophytes. However, the 
spore does not grow a leafy plant directly, but first produces 
an Alga-like filament which branches and creeps over the 
substratum (Fig. 375). From bud-like structures on this fila- 
ment, the leafy green plants grow, thus completing the life 
