BRYOPHYTES 
301 
lar thallus body, not at all resembling the "moss plant" 
of ordinary observation, and is not noticed by those una- 
ware of its existence. 
Presently one or more buds appear on the sides of this 
alga-like body (Fig. 275, b). A bud develops into an erect 
FIG. 275. Protonema of moss : A, very young protonema, showing spore (S) which 
has germinated it; B, older protonema, showing branching habit, remains of 
spore (s), rhizoids (r), and buds (>) of leafy branches (gametophores). After 
MULLER and THUKGAU. 
stalk upon which are numerous small leaves (Figs. 276, 290). 
This leafy stalk is the " moss plant " of ordinary observa- 
tion, and it will be noticed that it is simply an erect leafy 
branch from the prostrate alga-like body. 
At the top of this leafy branch sex-organs appear, cor- 
responding to the antheridia and oogonia of the Algae, and 
within them there are sperms and eggs. A sperm and egg 
fuse and an oospore is formed at the summit of the leafy 
branch. 
The oospore is not a resting spore, but germinates im- 
mediately, forming a structure entirely unlike the moss 
