12 CEREALS 
Fig. 1.—The oat (Avena sativa, 
Grass Family, Graminee). 
Plant in flower, showing sev- 
eral leafy stalks growing from 
one root. Three of the stalks 
bear flower-clusters. About 
one-fifth natural size. (Bail- 
lon.) 
guished (1) a lower swollen part, 
the ovary, containing a small egg- 
shaped body, the ovule; (2) a pair 
of elongated middle parts, the 
styles, each connecting the ovary 
with (3) a free, terminal part, 
the stigma, which is here like a 
little plume. Around the pistil © 
are three stamens very like what 
are commonly met with in other 
flowers. Each stamen consists 
of (1) a double sac, the anther, 
in which are produced innum- 
erable dust-like particles, the 
pollen, and (2) a threadlike part, 
the filament, on the upper end of 
which the anther is borne. When 
the anther is ripe it sheds its 
pollen, a particle of which com- 
ing to rest upon an oat stigma 
brings about the ripening of the 
ovule into a seed. As the ovule 
ripens, the ovary enlarges to keep 
pace with it, forming at last for 
the seed a firm protective cover- 
ing which together with the seed 
constitutes the grain. Mean- 
while the styles, stigmas, and 
stamens, having fulfilled their 
office, wither and fall off. The 
ripened ovary and its contents 
together with whatever parts 
ripen in connection with it (in 
this case two husks) constitute 
the fruit. 
Since the purpose of the flowe 
is to form seeds, and this is ac- 
complished by means of stamens 
and pistils, these are called the 
