THE PHYSIOLOGY OF SOWING SEEDs. 601 
the summit, and rising upward into the air. 
Growth is now rapid, but in a few days it 
seems to become stationary. It is then, that 
germination ceases. All the material of the 
seed has been expended in the formation of the 
seedling plant, and in storing its tissues with 
nutritive fluid. Yet, though apparently stationary, 
the plant is not inactive, other roots burst out 
from the bottom of the seedling plant ; and from 
the centre of the seedling blade springs up 
another blade. Vegetation commences—and the 
vigour of its action now depends upon the exter- 
nal conditions within the soil. But of this 
vegetative growth we see no portion of the ger- 
minative, or seedling plant partake; the first 
blade, or what Botanists call the cotyledon, soon 
becomes yellow, and has all its fluid absorbed, 
and then withers away. The same takes place 
with the radicals—-so that we ultimately find, that 
the germinative portions form no part of the real 
vegetating structure. And if in this our exam- 
ination of the seedling plants, any seeds have 
been buried too deep, and the germinative blade 
has had to elongate itself to reach the surface, 
then, we perceive above the seed, and near the 
surface of the soil, at the place of the first nodus, 
or joint, roots are thrown out, and the parts 
