The Indianapolis journal., 1886-04-11
PLANTS THAT EAT INSECTS.
The Peculiar Motions and Strange Evi-
denceS of Life in Various Plants.
A Lecture of Extraordinary Interest by In
diana's Distinguished Botanist, Delivered
Yesterday, to the School Children.

Prof. John M. Coulter of Wabash College,
gave lecture yesterday afternoon. at Fletcher
place Church. in the. penny course, to an audi
ence Of about five hundred children of the public
schools. His subject was "Plant Motion" and
was throughout, an illustration of the fact that
the most abstruse subjects in biology may be
presented with such interest and simplicity of
language and illustration as to be grasped and
enjoyed by the young.
Porfessor Coulter spoke Of the first discovery
of motion in the leaves of one of the common
tick-trefoils by an English lady, over one hun
dred years ago. She noticed that its two side
leaves alternately rose and fell by spasmodic
and gyratory motion. This set botanists to OBJ
serving and thinking about the cause
Of the motion, and other and SINH
lar motions were recorded in other species.
But the greatest discoveries were made and de-
scribed by Charles Darwin, in his book on the
motions of plants, notably that the growing stem
of the embryo twists around with corkscrew
motion, seeking the warmth and moisture of the
soil. Indeed, 1t seems as though all the brains
Of the plant are concentrated In it's growing stem
This is also seen in the motions of the stems of
hop-vnes and morning -glories. which sweep
around in spiral ascending circles. until they
grasp some support The morning glory COOS
always with the hands of a watch; the hop-vine
opposite to them. In the case Of the grape ten
drill, as soon 1t finds support the tendril forms
itself into a spiral spring, and thus draws the
vine up to the support All Of these motions
are due to some force within the plant itself.
second group of motions come from irrita-
tion of some part of the plants by external causes
Here Prof. Coulter made drawing and gave a
graphic account Of the Venus y-trap. which
Darwin regarded as the most curious and won
derful plant in the world. Though found for
merly anlong the fossils in the rocks of Japan
and central France, it is now only to be had
from a small region in Wilmington, Del. Upon
the inside faces of the little leaves Of this plant
not larger than a three cent piece are half q
dozen little hairs. When a fly touches these
hairs, the two halves of the leaf spring together
like steel trap and catch the fly before it can
escape. There ara interlocking teeth at the leaf
edges, which make the fly sure pris-
oner. 1t takes about two weeks for the
leaves to secrete kind of gastric juice and dis
solve, and digest, and absorb the nutrient parts
OF the fly. 1t ia q true insect eater. But If you
try to fool 1t by putting in piece Of wood, the
leaves shut and almost Immediately open out,
throwing the useless bit out
Almost like this plant is the sundew of the
tamarack swamps, in northern Indiana, which
has round leaves as big as the cross section of a
lead pencil. Around the edge of the leaf are
thirty or forty little hairs with knobs of sticky
jelly on their ends. which entrap insects, and
then bend over with their load onto the center
of the leaf, where the insect is digested and ab-
sorbed. If one knob cannot hold the insect it
asks those next to it 10 help, and they do So
The little drops, which glisten like dew in the
sun, are deadly playthings for insects to fool
with. They go off i've boys toy pistol.
A third kind of motion is that in which the
whole plant moves. These are all microscopic
plants, of jelly-like nature. Professor Coulter
said he had these little bits of jelly in tan
bark, and when exposed to light they would
glide away like snakes into the dark So we
have three kinds of motion: self-caused move
nents of the parts of plants irritative move
ments as of the sensitive plants, the fly trap and
the sundews and last the locomotory move
ments of the entire plant
Whatever plant we study. in its cells we find
honey-like fluid which is known as protoplasm
We find 1t wherever we find lfe whether in
plant or animal. 1t is the one substance com
mon to these two great branches of the tree of
life. But how the protoplasm causes the motion
and what is its relation to the life, the most
learned bOtanist or philosopher does not know
AS the eye does not see, but is the organ of sight
so protoplasm is not life. but Is only the origin
of life.
Prof. Coulter was listened to with marked at
tention-not less so by the youth than by the
teachers and citizens scattered through the
audience. There were about three girls to each
boy-the same discrepancy in all the higher
grades OF schools Prof. Coulter stated to q
friend that the young people were more atten-
tive than most older audiences, and that he had
enjoyed their work-the uniform testimony of
all that can adapt themselves to the needs of
youth