Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-05-13

We have received another interesting
and valuable contribution 10 the science Of
vegetable life and force from the pen of
President Clark, of the Massachusetts
Agricultural College at Amherst. Our
readers will remember the account we
gave, about year ago, of the experiments
In regard to the force Of sap, which were
conducted under his directions, and also
the later account of the lifting power of .
growing squash. The latter experiments
were conducted last summer at the Agri-
cultural College, and the result was that Il
single squash, so guarded that the lateral
pressure was restrained, lifted In its growth
the enormous weight of two tons and "a
half without being crushed,
The history Of these experiments forms
the basis of this treatise, which n Illus
trated by numerous engrayings, but many
important subjects connected with plant
life, and especially the power and habits
of plants in growth, are discussed by one
who proves himself Il master in this de-
partment of science. We make the fol.
lowing extracts:
"During the past year much has been
written and said about carniyorous plants
which catch great numbers Of insects for
the apparent purpose Of feeding upon
them. When fly alights on the leaf OF n
Di0n1a, the two halves close upon 1t and
hold Ii fast until consumed, when they
open for another. The leaf OF species OF
DroseTu, in New Jersey, Is said To have
the power Of moving toward an insect,
fastened within half an inch Of 1t, and
feeding upon it, The pitcher shaped
leaves OF lSarrdceHta pdTf0Larts not only
seem 10 possess the power OF enticing in
scots 10 climb from the ground 10 the in.
side Of their pitchers, by secretlng yerti.
cal line Of honey on the outside, and also
a line around the edge Of the cup, but they
prevent their escape by an ingenious ar
rangement of hairs, which continually
force them downward a. they attempt 10
fiy out When they thus reach the bot
tom Of their prison they come in contact
with fluid which first paralyzes them
and then hastens their decay and absorb
ton.
T" Not less wonderful are the instructive
movements by which climbing plants
seek for and attach themselves To a sup
port. Twining vines, like the hop, the
bean and the morning glory, exhibit a re.
yolying movement OF their extremities
until they come i'm contact with some OBJ
iect around which TO coil Each species
has its own peculiar direction, from which
most OF them never vary. A few, like the
hon. wind from the right upward toward
the left, moving like the hands OF watch (;
but most, like the bean, move in an oppo
site direction. The squash, however, is
not twinng plant, but climbs by means
Of tendrils. Nevertheless, the tip OF a
growing vine rcvolves continually from
Jeff over 10 right, in evident search for a
support
If a single be set into the ground near
The tip Of growing squash-yine II will in
a day or two be seen turning toward it,;
and that il The single be removed 10 the
oppositc side the direction of the vine
will again be changed. He also states
that he has observed squash-yine, after
running along on the ground ten or twelve
feet. and then passing under the branches
Of n tree which were four feet above IL, 10
stop and turn upward toward the branches.
After growing ia this direction till itcould
no longer sustain itself, the vine fell 10 the
ground: but instead Of proceeding hori-
zontally il again rose into the air, again TO
fail. A third effort was made before the
plant was willing 10 give up and trail
humbly on the earth.
The end Of the vine under observation
was constantly elevated 10 the sash-bars
and glass above IL, sometimes 10 the height
OF two feet, and ~ it increased In length
was pushed along against them. The ex.
tent and velocityaof the terminal motion
were doubtless greatest in August, when
growth was most rapid. The record, how
ever, was made in November. The time
occupied in each revolution was variable,
and the long diameter Of the ellipse de