Page 99 - My FlipBook

out of the grain and into the earth and it is beginning to
gather its own food for the plant.
It is an interesting series of studies, one that is easily
performed. Anyone fairly well versed in the handling of
the microscope and the cutting of sections can, by a little
study of staining agents, follow the disappearance of the
starch, the motion of the sugar through these ducts and into
the grain, and then see that it is lost to the staining reagents
as it is woven into the tissue of the plant.
Of course, that is a somewhat rough following of these
processes. We do not know the chemical processes through
which this passes before it is woven into the tissues of the
plant, but that these chemical forms are changed and that it
is finally woven into the protoplasm of the plant there can be
no question by anyone who follows these observations
through with a fair degree of care.

Root Pads.

Now another thing happens. Here we have the diges-
tion, the nutrition and the growth. Upon this root end here
we will discover ducts, and almost immediately it passes out
of the grain we will find a development on here of what is
known as the root pad, which is composed of round or polyg-
onal cells, soft bodies of cells with more or less of an epi-
thelial structure upon its surface all around.
Sachs has performed a very wonderful experiment in the
study of these root pads, which I have repeated myself a num-
ber of times. If the grains of corn are planted upon a piece
of poHshed marble and they are allowed to grow until the
rootlets have struck down upon the marble and allowed to
spread out upon it (they cannot penetrate the marble), and
have grown in that position for a time, he tips the whole thing
off of the marble, washes it and finds the trace of every Httle
rootlet in a roughening of the polish of that marble wherever
they have passed along upon it. Why is that so? This little
root pad is another digestive organ and it throws out a secre-
tion that dissolves foodstuff, prepares it for absorption, takes
it in and passes it along these little ducts into the plant for
its nutrition. And these little root pads will form a secre-
tion that will dissolve materials that are insoluble in water.

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