The Worcester spy. [volume] (Worcester, Mass.) 1898-1904, 1899-04-23
HOW PLANTS GET FOOD.
An Interesting Discussion of the Subject
at the Natural History Museum. :,


at the Natural History Museum. ,
Miss Martha F. Goddard in speak
ing of THE food question in the plant
world, says in respect to land plants
The mother plant supplies in its seed,
enveloped in strong waterproof en-
velope and sometimes supplied with
acid to serve to repel animals. a. suf
ficient amount of food to serve until
the infant plant can. provide for it
self.
1t is desirable, too, that the prospect
i've plant should be set at a distance
from home as that locality may be al
ready impoverished by the mother
plant. So provisions are made for
scattering the seeds by the violent
bursting of the pods, by providing a
fieshy envelope palatable to animals
by hooks for attaching them to ami
mails, or by wings or parachutes in
order that they may he carried ny the
winds, or by hollow bodies so that they
may be transported by water.
Having arrived in a new locality,
they are fixed there by mucilasinous
coats or hairs, or hooks or projections
The plant, apparently takes care that
the development of the seed into the
independent plant shall be delayed I'M
til supplied with favorable conditions
in the way of temper as~re, mcistureS
sunlight and food. The elements need
ed by the growing, Towering plant are
carbon hydrogen, oxygen, nitrogen,
sulphur, phosphorus, potassium. cale-
ium, magnesium and iron. These 10 sub
Or.falac
plant ard come from the soil, except
the oxyden and carbon; one or more of
IA other elements may be accessory to
the plant. After the termination of
the seed. the radicle descends and a root
is formed with root hairs. These lat
ter, by a process called osmosis, abb
sorb from the soil water which contains
the substances necessary for the grow
ing plant. This absorption is regulated
by selective activity of protoplasm pre-
sent. and the solution is sent through
path ducts to the leaves.
The propelling force is not wholly I'M
derstood but important factors are
thought to be root pressure and less
ening of pressure by corporation
Transportation from the surface of
leaves. This Transportation is great and
necessary. because the solutions alb
sorbed by the root-hairs are weak, and
II Is IeS ny uOieS Called SlOiHdld
on the under surface of the leaves
1t is lessened, too, in hot, dry eli
mates by the small size of leaves or
their absence. by the thickness of the
epidermis, the rolling of leaves, dead
hairs and incrustations of lime 1t is
increased in warm. moist places by
large leaves, thinness of epidermis, con-
trivances for. preventing the wetting of
leaVes-WaX. hairs, channels for drain
age, and position of leaves.
Carbon and oxygen necessary are ia
ken in from the air by the leaf cells.
Green chlorophyll cells of the leaves
make sugar and starch for the plant
from carbon dioxide in strong light.
Cells of the plant, chiefly of the leaves,
make proteids from heterogeneous food
and starch. -
Starch which has been formed is used
in growth, in the formation of cell
walls, is the manufacture of proteids
and stored in the seeds and in the cells
of stem and root. Proteids formed go
to increase the amount of protopasm
for growth and are stored up as re-
serve. The devices of the plant to Sc
cure sufficient food and water are:
Arrangement of leaves or stem to Sc
cure all the sunlight possible, adapta-
ton of leaves by form and position to
conduct rain water to the ground di-
rectly over the root hairs, and growth
of root hairs only where effective. The
lecture was illustrated by charts and
growing plants and was very interest
ing.