‘CHAPTER III 
~MOVEMENTS, DEVELOPMENT, AND MORPHOLOGY OF 
THE SEEDLING 
32. How the Seedling breaks Ground. — As the student 
has already learned by his own observations, the seedling 
does not always push its way straight out of the ground. 
Corn, like all the other grains and grasses, it is true, sends 
a tightly rolled, pointed leaf vertically upward into the 
air. But the other seedlings examined usually will not 
be found to do anything of the sort. The i? seedling 
is a good one in which to study what may 
be called the arched hypocotyl 
type of germination. If the 
seed when planted is laid hori- ‘mo 
fy, G 
A B Cc D E 
, Fic. 9.—Successive Stages in the Life History of the Squash Seedling. 
GG, the surface of the ground; r, primary root; r’, secondary root; c, hypocotyl; —_ eee 
a, arch of 3 co, cotyledons. 
zontally on one of its broad surfaces, it usually goes through 
some such changes of position as are shown in Fig. 9. 
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