306 
PLANT STUDIES 
of the capsule like a loose cap or hood, known as the 
calyptra (Fig. 276, c), which sooner or later falls off. As 
stated before, the ma- 
ture structure devel- 
oped from the oospore 
is called a sporogoni- 
um, a form of sporo- 
phyte peculiar to the 
Bryophytes. 
201. The sporogoni- 
um. In its fullest de- 
velopment the sporogo- 
nium is differentiated 
into the three regions, 
foot, seta, and capsule 
(Fig. 276) ; but in some 
forms the seta may be 
lacking, and in others 
the foot also, the sporo- 
gonium in this last 
case being only the 
capsule or spore case, 
which, after all, is the 
essential part of any 
sporogonium. 
At first the capsule 
is solid, and its cells 
are all alike. Later a 
group of cells within 
begins to differ in ap- 
pearance from those 
about them, being set 
apart for the produc- 
tion of spores. This 
initial group of spore-producing cells is called the arche- 
sporium, a word meaning " the beginning of spores." 
FIG. 279. Sporogonium of Funaria : A, an em- 
bryo sporogonium (/,/')> developing within 
the venter (, b) of an archegonium ; B, C, 
gonia, pushing up calyptra (c) and archego- 
nium neck (h), and sending the foot down 
into the apex of the gametophore. After 
GOEBEL. 
