MANUAL OF NATURE STUDY. 
139 
to tlie ground, or brick, or whatever their home 
may be, until finally, after branching profusely, 
they give rise to very tiny lateral buds, which, 
in time, grow into moss-plants that bear the re¬ 
productive organs called antheridia and archegonia. 
The fern plant is asexual, while the moss plant is 
sexual. 
Though the fern plant has neither male nor fe¬ 
male reproductive organs, it is at the same time able 
to produce spores which fall to the ground and devel¬ 
op sexual plants called prothalia , from which sexless 
or asexual fern plants once more arise. 
Now the history of the moss plant, though pro¬ 
duced by “alternation of generations,” is somewhat 
different from that of the fern. In the moss, the 
more conspicious moss plant is sexual. It bears 
male and female organs, and an egg-cell is fertilized 
by a male element. The fertilized egg-cell remains 
attached to the mother plant and develops into a 
tiny sexual stalk which bears on its apex the spec¬ 
ial reproductive cells or spores. These spores fall 
to the ground as did the fern spores, and there grow 
into a usually thread-like structure, the protenema , 
from which the sexual moss-plants arise from buds. 
In the fern asexual generation was the more 
conspicuous; in the mosses, the sexual genera¬ 
tions are more conspicuous. 
