6 ELEMENTARY BOTANY 
(Latin seutwm, a shield) ; this answers in part to the cotyledon. 
The rest of the grain, chiefly yellow, is food material. 



Fies. 4 to 7.—Maize. 
4, EXTERNAL VIEW OF GRAIN. 5.—EmBRyYO, 
REMOVED FROM GRAIN. 
lateral roots. 
6 AND 7,—SEEDLINGS. 
x, remains of style; y, stalk of attachment 
to cob; sc, scutellum ; p, plumule; 7, radicle ; 
sh, root-sheath ; rh, root-hairs ; e, food-material. 
Stages in [he first 
Germination. step in 
germination is in- 
variably the swelling 
of the seed owing 
to the taking in of 
water; then the skin 
_ bursts in consequence 
of the pressure of 
the radicle against 
it; this soon pro- 
- trudes, and the skin 
oes on splitting 
until the plumule 
also emerges. ‘lhe 
radicle soon gives 
off branches forming 
In maize, two other roots, called secondary, 
arise from the scutellum. The first root has a little sheath at its 
base, so that it is possible to tell which the primary root is. 
The plumule grows into the shoot; in maize the leaves 
ensheathe the stem. 
COMPARISON OF SEED OF BEAN AND 
GRAIN OF MAIZE. 
BEAN. . 
I. A seed. 
2. Brown skin is testa. 
3. Two fleshy cotyledons, 
containing food. 
4. Food stored within the 
young plant. 
5. Radicle develops into 
primary root, bearing 
lateral branches. 
6. Plumule grows into shoot. 
MAIZE. 
A seed + seed-vessel. 
Skin is testa + wall of seed- 
vessel. 
One cotyledon. 
Food supply external to the 
young plant. 
Radicle develops into primary 
root with lateral branches ; 
in addition there are two 
other roots, which are 
soon as long as_ the 
primary root. 
Plumule grows into shoot. 
