58 ELEMENTARY BOTANY 
Whilst developing, the embryo feeds on the endosperm. 
Sometimes all this food material is absorbed during the ripening 
of the seed, but sometimes not until ger- 
mination. In the first case the seed is 
said to be ecalbuminous, that is, without 
albumen ; in the latter it is albuminous. 
‘This term “albumen” denotes the 
chemical composition of which the endo- 
sperm or food material is composed and 
is still retained in botany, because it is 
usual and convenient to speak of seeds 
as albuminous or exalbuminous. The 
: term “endosperm” is a better one, and 
apres ee Aege denotes exactly the same part of the 
purtine our Tusz seed as that designated “albumen.” The 
Ne ea bean seed, described in Chapter I, is 
p.t, pollen tube; e.s, exalbuminous, for it consists simply of 
ee ME ea testa and embryo. On the other hand, 
ments; k, lower the maize seed is albuminous, for it 
part of calyx cup. = contains in addition to testa and 
embryo, the endosperm, which occupies the greater part of 
the seed. 

TABLE SHOWING FORMATION OF SEED FROM 
: OVULE. 
OVULE. SEED. 
I. Stalk. I. Stalk of attachment. 
2. Usually two integuments. 2. The testa. 
3. Micropyle. 3. Hole in testa, also called 
micropyle. 
4. MacrosporeorEmbryo-sac. 4. Embryo + endosperm, 
which may, or may not, 
be absorbed byembryo. 
5. Oosphere. : 5. Embryo. 
A seed is therefore a macrosporangium, enclosing a young 
plant, the embryo, which is set free from the parent plant 
in order to produce a new plant. Only Flowering Plants form 
