BEYOPHYTES 303 
duces only sexual spores (oospores), arid therefore produces 
sex organs and gametes. It is known, therefore, as the 
gametophyte that is, " the gamete plant." 
The generation which consists of the "spore fruit" 
that is, leafless stalk and spore case produces only asexual 
spores, and is called the sporophyte that is, "the spore 
plant." 
The relation between the two alternating generations 
may be indicated clearly by the following formula, in 
which G and S are used for gametophyte and sporophyte 
respectively : 
Gz:g>o S o G:z:8>o S o G, etc. 
The formula indicates that the gametophyte produces 
two gametes (sperm and egg), which fuse to form an oospore, 
which produces the sporophyte, which produces an asexual 
spore, which produces a gametophyte, etc. 
In reference to the sporophytes and gametophytes of 
Bryophytes two peculiarities may be mentioned at this 
point : (1) the sporophyte is dependent upon the gameto- 
phyte for its nourishment, and remains attached to it ; (2) 
the gametophyte is the special chlorophyll-generation, and 
hence is the more conspicuous. 
If the ordinary terms in reference to Mosses be fitted 
to the facts given above, it is evident that the " moss 
plant " is the leafy branch of the gametophyte ; that the 
" moss fruit " is the sporophyte ; and that the alga-like 
part of the gametophyte has escaped attention and a 
common name. 
The names now given to the different structures which 
appear in this life history are as follows : The alga-like part 
of the gametophyte is the protonema, the leafy branch is 
the gametopliore (" gamete-bearer"") ; the whole sporophyte 
is the sporogonium (a name given to this peculiar leafless 
sporophyte of Bryophytes), the stalk-like portion is the seta, 
the part imbedded in the gametophore is the foot, and the 
urn-like spore-case is the capsule. 
