46 BOTANY 
bursting away the skin and pushing with their tender 
erowing points, to light, air, and freedom. If the 
delicate plumule were to be pushed upward through 
the rough soil it would be in danger of sustaining 
serious injury, but, when pulled out with the apex 
pointing into the earth, this danger is much reduced. 
By observing the illustrations it will be seen that there 
are two main methods of escape. A loop is formed 
either in the stem immediately above or in the hypo- 
cotyl immediately below the cotyledons. All depends on 
the position of this loop. When it is formed in the 
stem above the cotyledons the plumule alone is pulled 
from the ground, and the cotyledons remain in the 
earth. This type, well illustrated in the broad bean 
(Fig. 28), is called hypogean (Gk. hypo under, and ge 
the earth). Where the loop is formed in the hypocotyl 
the cotyledons are pulled out of the cover and appear 
above ground. This type, shown in the marrow, 
French bean, and castor bean (Figs. 25-27), is termed 
epigean (Gk. epi upon, and ge the earth). In the 
pumpkin, it will be observed, there is a remarkable: 
peg which is of great assistance to the cotyledons in 
freeing themselves of their covers. 
In most monoecotyledons, such as maize (Fig. 30) 
and wheat, the plumule emerges from the seed and 
makes its way straight upwards into the air, but in 
the onion (Fig. 29) a most peculiar development takes: 
place. The cotyledon itself, which is long and slender, 
forms a loop by means of which it backs out of the seed. 
The tip of the cotyledon remains for a considerable: 
time, coiled like a watch-spring, embedded in the 
endosperm from which it absorbs nourishment till its: 
final escape. Something very similar happens in the 
date (Fig. 31). 
The net result of this investigation of seeds and 
their germination, is to show that, though the broad 
features are the same in all cases, yet each type has its: 
