380 
AMERICAN AG-RICULTURIST 
[December, 
VENUS’S FLT TRAP {Bioncea nvuscipula.) 
The Movements of Plants. 
There are some plants ■which, by their sud¬ 
den movements ■when irritated, justly excite our 
■wonder. The Sensitive Plant {^Mimosa pudica\ 
is one of the most familiar of these, and is one 
■which can readily be raised, as the seeds, ■which 
may be had at the seed stores, ■will germinate in 
the open ground. A portion of the sensitive 
plant ■was figured in December of last year on 
page 349. Its leaves upon the slightest touch 
suddenly close and droop, and after a short time 
gradually unfold. Another remarkable instance 
of irritability in plants is shown in the Venus’s 
Fly-Trail {Bioncea muscipula), a native of our 
Southern States. We give a figure of this plant 
taken from one of the admirable illustrations in 
Gray’s Genera. The plant is here represented 
of life size, and the peculiar leaves are ■u’ell 
shown in various positions. The petiole or leaf 
stalk is very broad, and the proper blade, ■which 
is short in proportion, consists of two rounded 
lobes, each of which bears upon its margin a 
row of short bristle-like hairs, and upon its up¬ 
per surface a few scattered minute hairs, ■which 
seem to be the seat of sensitiveness. When an 
insect alights upon the leaf and touches one of 
these hairs, the two lobes immediately close and 
secure the insect which is held until dead. 
One of the leaves is shown closed in the en¬ 
graving, the marginal bristles interlocking in 
the manner of the fingers when the hands are 
clasped. Why a plant should be provided with 
so complete a contrivance for trapping insects 
is not understood, but it does it most efiectually, 
and its operation affords us another striking in- 
stance of sudden motion in plants, when sub¬ 
jected to some irritating cause. But there are 
instances in which the movement is sponta¬ 
neous, i. e., without any apparent exciting cause. 
A plant of the East Indies, Heclysarum gyrans, 
in the warm air of the hot-house, keeps its leaf¬ 
lets constantly in motion. Other instances oc¬ 
cur of spontaneous motion, which is so slow that 
■we notice only its effects. We have all of us 
noticed the climbers after they had wound them¬ 
selves around some support, and it is a matter 
of observation that this is sometimes with the 
sun, and at others in an opposite direction, and 
though the manner in which climbers twine 
about objects had at¬ 
tracted sorne atten¬ 
tion from scientific 
observers, it is only 
recently that the sub¬ 
ject has been thor¬ 
oughly investigated. 
Darwin, the well- 
known English na¬ 
turalist has publish¬ 
ed the results of his 
experiments in a 
most interesting pa¬ 
per in the Transac¬ 
tions of the Linnsean 
Society, for June 
1865. We can only 
call attention to a 
few of the points in 
this investigation that 
seem to be of gene¬ 
ral interest. When 
the growing end of a 
twining plant hangs 
without support, it 
bends over in a more 
or less horizontal di¬ 
rection, and contin¬ 
ues to sweep around 
in search of some object around which to 
twine. In doing this, the extremity of the 
branch describes a circle or ellipse vidiich 
widens as the shoot increases in length. The 
time occupied in making these revolutions va¬ 
ries in different plants, and also in the same 
plant under different circumstances. The shoots 
of common Pole-beans and of Morning Glo¬ 
ries revolve in about two hours, while other 
climbers occupy 24 to 50 hours in completing 
the circle. The top of a Ceropegia, a green¬ 
house climber, 31 inches in length, revolved day 
and night, describing a circle of over 5 feet in 
diameter, about once in 6 hours. This motion 
Darwin remarks is not a twisting, but that “the 
movement is in fact a continuous self-bowing of 
the whole shoot, successively directed to all 
parts of the compass.” * * * “When at last 
the revolving shoot meets with a support, the 
motion at the point of contact is necessarily 
arrested, but the fi'ee projecting part goes on re¬ 
volving. Almost immediately another and up¬ 
per point of the shoot is brought in contact 
with the support and is arrested; and so on¬ 
ward to the extremity of the shoot; and thus 
it winds around its support.” Tlie whole of 
the interesting article, from which the above 
is quoted, would occupy several pages of the 
Agriculturist^ and we must content ourselves 
with calling the attention of those curious in 
such matters to these readily observed pheno¬ 
mena. We must leave some notice of Darwin’s 
observations on those plants which climb by 
means of tendrils and by twisting their leaf¬ 
stalks for an article in a future number. 
--- - - 
A Pretty Climbing Solannm. 
Bolanum jasminoides. 
In noticing ornamental plants, ■we generally 
select those which may be readily obtained by 
the reader in any part of the country where 
there are nurserymen and seedsmen. Some¬ 
times there are plants we would like to intro¬ 
duce to our readers, but are deterred from do¬ 
ing so, from the fact that they are not generally 
to be found in the hands of the dealers. Per¬ 
haps the best way in such cases is to notice 
the plant, and thus create a demand for it, 
which the florists will soon try to meet. But 
few have an idea of how much popularity is 
given to a plant or implement by a figure and 
CLIMBING SOLANUM. 
description in the Agriculturist. Among the 
many thousands who read the article, there will 
be a sulficient number order plants, etc., to ex¬ 
haust any ordinary stock. One of our largest 
dealers in seeds and plants says that he can tell 
by his orders wliat plants have been recently 
recommended in this journal. We are led 
into these prefatory remarks by recollecting that 
the plant we have had figured is not one of 
those that the florists make much stir about. 
