Chap. III.] DOWNWARD GROWTH OF THE ROOT. 
101 
the flower-pot. They, however, ceased to grow, 
being possibly beaten down by the watering. 
Probably one reason which enables these deli¬ 
cate organisations to dispense with the crane- 
neck in thrusting themselves through the hard 
earth is, that they are entirely single-leadered, 
instead of having leaflets branching sideways 
like the gemmules of double-seeded plantules. 
But, besides this, the single, tender blade is 
rolled round on itself, and enveloped in a coarse, 
thick, white outer coating, pointed at the top. 
The instant the point of this tough sheath clears 
the earth, it opens and emits the green blade 
unscathed into the air. Here is again a beau¬ 
tiful contrivance . The barley and oats growing 
from below, ripened their seed, which grew when 
sowed. 
1 have not known an instance of a garden 
bean getting the head of its first gemmule below 
the wire; though, when the head was engaged 
above, the stalk would bow down, and in this 
state the branch-roots fixed themselves, and the 
plant grew, and threw out new shoots from the 
knots and from the neck, which grew towards 
the light: and I think that the organisation of 
the first gemmule of the garden bean, and, per¬ 
haps, the first gemmule of all plants, is different 
Provision to 
enable the gem¬ 
mule of a single- 
seeded plant to 
thrust itself 
through the 
earth. 
Probable dis¬ 
tinct organisa¬ 
tion of first 
gemmule. 
