Evening star., 1940-01-16
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study

vs. sSsSl eSHVs0SSuy
And Study
BY Thomas r. Henry.
Plants are the great biological democ-
racies, while animals. man included,
are autocracies.
Such Is the philosophical conclusion
OF Prot. r. W. Went, plant psychologist
Of the California Institute Of Tech
nology. now on . national lecture tour
under the auspices Of the Sigma XII
Society. sag
Both plants and animals, he says
are communities Of countless billions
Of single cells which somehow, in the
long course Of evolution. have learned
to live together in co-ordinated socie-
ties. In animals the coordination of
the parts Of the body is determined by
. super-regulating center, the brain.
1t can best be compared with the func-
tloning Of totalitarian state. A Sec
ond way to achieve coordination is by
the democratic principle, in which a
living organism arrives at q state where
one group Of cells becomes dependent
on other cells, recognizes this depend
ence, and plays its part without COM
pulsion. #
In the case Of plants, DR.. Went said.
this interdependence may involve the
loss OF ability Of some cells to create
substances needed for growth. II other
cells retain this ability, but, in turn,
lose some other substance, they become
mutually dependent and an organism
Is formed.
'The unity Of such an organism"
Prof. Went said, "is insured in a re-
markable way. One part cannot develop
to greater degree than the size Of the
other part permits. There is no regi-
mentation, but mutual interdependence.
This Is very typical Of the democratic
principle. This same principle is the
one which causes the plant to develop
as unit. There are no nervous centers
which direct the different parts, but,
by being interdependent, the top can
not develop any further than the size
OF the root system allows. and con-
versely. the root system depends on the
top for its growth"
These checks and balances, so char.
acteristic of democracy, Prof. Went
said. are obtained in plants through
plant hormones, chemical messengers
stimulating such growth in various parts
OF the body as other parts permit.
Typical are the hormones promoting
root growth, which are produced by
tips Of growing shoots Of the plants.
IN these times when the democracies
have such q difficult time in standing
up against relationships" Prof. Went
said. ut probably will not surprise you
to hear that. plants also have to cope
with efforts to curb their independence.
These efforts come from man. As long
as the intricate mechanism of the plant
democracy was unknown, man had only
one way to increase the yield of a plant
product. This was by improving the
growing conditions of the whole plant.
Now new possibilities present them
selves. II we know exactly the factors
which are required for growth Of the
specific organs we need, it might be
possible to supply these artiicially. In
such way the strength Of the plant
would not have to be equally dis
tributed over all its organs, but we
might be able to direct its develop.
ment according to our special needs.
Tho same effect is produced by
selection. Certain plants which are
genetically unbalanced will have an
excessive leaf production, such IS cab
bage. or flower production. such as
caulifower. ..
by using plant hormones normal
plants can be induced to form the
same sort Of unbalanced growth. Since
the plant hormones are effective in
such minute amounts their practical
use Is possible also from an economic
standpoint. The simplest example of
such unbalanced growth due to arti-
ficial application Of growth factors is
the root growth in vitro. In that case
the presence Of the rest Of the plant
is entirely superfluous. Offhand, how
ever. it does not seem practical to grow
carrots or beets in this way since we
have to supply sugars as well as vitamin
B /, as well as the root growth
hormones. In other cases unbalanced
growth may be used commercially.
'The first Of these cases is the root
ing of cuttings. Normally leafy shoot
Of plant produces root-forming fac
tors. which ultimately will reach the
root system and help build 1t up. If
the shoot is cut of and made into a
cutting this production of hormones
continues. The hormones will accumu-
late near the cut surface This often
leads to differentiation Of roots and
roofing Of the cutting In many cases,
however, the hormone production is
inadequate to initiate roots at the cut
surface and the cutting will die without
roofing. In remarkable number of
such cases auxin application is effec-
tive and will result In successful root
ing of the cuttings.
TN other cases it has been reported
that the set of fruit could be consider
ably improved by spraying trees pre-
vious to period Of excessive fruit drop
soon after Towering. Here we stand
only at the beginning. Improved germ
ination, better seeding growth, more
abundant Towering are all effects
claimed to result from treatment with
small amounts of auxins"