Knoxville journal. [volume] (Knoxville, Iowa) 1874-1986, 1875-05-13
scribed, which was horizontal, measur


scribed, which was horizontal, measur
about two inches.
THE tendrils ofthe squash-vine were pro-
duced at the nodes, and the main stalk was
hollow and divided into several branches
at point three or four inches distant from
the vine. These branches spread out in
various directions and attained length
of six or eight inches. Each branch grad
uaiiy Strengthened out from the coil in
which it first appeared and increased in
length. When about two-thirds devel-
oped 1t began to revolve, SO that its hooked
tip described an ellipse several inches in
diameter. Its revolution was made by a
series of bendings, in such way as
not to twist ITSELF The tendrils moved In
the same direction with the tip of the vine,
but somewhat irregularly both as to time
and TO the figure described During the
day the ellipse was broad and at nigh
long and narrow. Usually the motion
was scarcely perceptible to the eye, but
sometimes it moved two inches in five
minutes, The average time of revolution
in November was about three hours. Ii
touched by the finger on the sensitive or
inner side the tendril bent toward the
place where the finger was, and, not find
ing it, Strengthened itself again. If how
NNNi ~ tuihC III NputstSt With stHS oUItNb u
which ii could cling it bent at the point of
contact and the concave curvature ex-
tended along the inside of the branch
until the extremity was wound closely
around the support. Other branches
would also fasten TO the same object, If
possible. The tendril, thus attached in
creased in size and tirmness, and soon
coiled upon itself in double-reversed
spiral, so as to exert strain on the sup.
port. All the branches having done this
they pull together and must fail together
if at all.
Another most obvious benefit derived
from this double spiral is the elasticity Of
the fastening, which greatly diminishes
the danger of rupture by violence. If the
tendrils of the squash failed lin finding u
support the branches then coiled upon
themselves and the main stalk often
turned back along the vine.
THE habits of climbing plants have
been studied by Mr.. Charles Darwin and
others; but this field for research is by no
means exhausted. The tendrils of the
grape vine are not very sensitive, but
fasten themselves very firmly to suitable
support. The tendrils of the cobed scdndens
are long, branching and tipped with woody
claws. They are extensions of the petiole
of a compound leaf, revolve actively and
attach themselves in marvellous manner.
When revolving branch has found
support it contracts so rs To bring its ex-
tremities In contact with it, The other
branches seek the same object. and as
they are sensitive on all sides they fail in
many cases to secure q firm attachment
with their claws. They therefore detach
themselves from their support, one at
time In succession, twist so rs to bring
their claws into proper direction, and then
again make fast.
Z" Ii is well known that most plants
grow toward the strongest light; but
climbing plants are sometimes exceptions.
English ivy turns its young shoots away
gom the light In order that they may
come in contact with dark objects--such
as rocks and trunks of trees-to which
they then attach themselves by short
roots. The tendrils of the Virginia creep
or or woodbne are among the most won
derful. They grow away from the light,
and send their branches into crevices of
old bark and rocks. Sometimes such ten
drills are said by Mr. Darwin 10 actually
show power of choosing one place of
attachment in preference 10 another, by
penetrating cavity and then Withdrawing
TO seek more satisfactory one. As soon
as the tendrils of the creeper find a sup
port, the branches spread out their tips
and press them against IT, Little pads of
hard, cellular tissues are now developed
at the points of contact, and the tendril
coils on itself and becomes very tough
and woody. At the end of the first sea
son ii dies, but remains firmly fixed 10 its
support for many years. Mr.. Darwin
foun done, which, though ten years old,
was not detached by weight of ten
pounds from the wall to which II had adj
hered. IN. Y. Observer.