A	>>	B	>>	C	>>	D	>>	E
F	>>	G	>>	H	>>	I	>>	J
K	>>	L	>>	M	>>	N	>>	O
P	>>	R	>>	S	>>	T	>>	U
V	>>	W	>>			X	>>	Z

Charles Dickens - "Hunted Down"

H. Rider Haggard - "King Solomon's Mines"

Rudyard Kipling - "Puck of Pook's Hill"

Sarojini Naidu - "The Golden Threshold"

The Movements and Habits of Climbing Plants

C >> Charles Darwin >> The Movements and Habits of Climbing Plants




{34} Prof. Asa Gray informs me that the tendrils of P. sicyoides
revolve even at a quicker rate than those of P. gracilis; four
revolutions were completed (the temperature varying from 88 degrees-
92 degrees Fahr.) in the following times, 40 m., 45 m., 38.5 m., and
46 m. One half-revolution was performed in 15 m.

{35} See M. Isid. Leon in Bull. Soc. Bot. de France, tom. v. 1858,
p. 650. Dr. H. de Vries points out (p. 306) that I have overlooked,
in the first edition of this essay, the following sentence by Mohl:
"After a tendril has caught a support, it begins in some days to wind
into a spire, which, since the tendril is made fast at both
extremities, must of necessity be in some places to the right, in
others to the left." But I am not surprised that this brief
sentence, without any further explanation did not attract my
attention.

{36} Sachs, however ('Text-Book of Botany,' Eng. Translation, 1875,
p. 280), has shown that which I overlooked, namely, that the tendrils
of different species are adapted to clasp supports of different
thicknesses. He further shows that after a tendril has clasped a
support it subsequently tightens its hold.

{37} Annales des Sc. Nat. Bot. 4th series, tom. xii. p. 89.

{38} It occurred to me that the movement of notation and that from a
touch might be differently affected by anaesthetics, in the same
manner as Paul Bert has shown to be the case with the sleep-movements
of Mimosa and those from a touch. I tried the common pea and
Passiflora gracilis, but I succeeded only in observing that both
movements were unaffected by exposure for 1.5 hrs. to a rather large
dose of sulphuric ether. In this respect they present a wonderful
contrast with Drosera, owing no doubt to the presence of absorbent
glands in the latter plant.

{39} Text-Book of Botany, 1875, p. 779.

{40} Journal of Linn. Soc. vol. ix. p. 348. Professor G. Jaeger has
well remarked ('In Sachen Darwin's, insbesondere contra Wigand,'
1874, p. 106) that it is highly characteristic of climbing plants to
produce thin, elongated, and flexible stems. He further remarks that
plants growing beneath other and taller species or trees, are
naturally those which would be developed into climbers; anti such
plants, from stretching towards the light, and from not being much
agitated by the wind, tend to produce long, thin and flexible shoots.

{41} Professor Asa Gray has explained, as it would appear, this
difficulty in his review (American Journal of Science, vol. xl. Sept.
1865, p. 282) of the present work. He has observed that the strong
summer shoots of the Michigan rose (Rosa setigera) are strongly
disposed to push into dark crevices and away from the light, so that
they would be almost sure to place themselves under a trellis. He
adds that the lateral shoots, made on the following spring emerged
from the trellis as they sought the light.

{42} Mr. Spiller has recently shown (Chemical Society, Feb. 16,
1865), in a paper on the oxidation of india-rubber or caoutchouc,
that this substance, when exposed in a fine state of division to the
air, gradually becomes converted into brittle, resinous matter, very
similar to shell-lac.

{43} Fritz Muller informs me that he saw in the forests of South
Brazil numerous black strings, from some lines to nearly an inch in
diameter, winding spirally round the trunks of gigantic trees. At
first sight he thought that they were the stems of twining plants
which were thus ascending the trees: but he afterwards found that
they were the aerial roots of a Philodendron which grew on the
branches above. These roots therefore seem to be true twiners,
though they use their powers to descend, instead of to ascend like
twining plants. The aerial roots of some other species of
Philodendron hang vertically downwards, sometimes for a length of
more than fifty feet.

{44} Quoted by Cohn, in his remarkable memoir, "Contractile Gewebe
im Pflanzenreiche," 'Abhandl. der Schlesischen Gesell. 1861, Heft i.
s. 35.

{45} Such slight spontaneous movements, I now find, have been for
some time known to occur, for instance with the flower-stems of
Brassica napus and with the leaves of many plants: Sachs' 'Text-Book
of Botany' 1875, pp. 766, 785. Fritz Muller also has shown in
relation to our present subject ('Jenaischen Zeitschrift,' Bd. V.
Heft 2, p. 133) that the stems, whilst young, of an Alisma and of a
Linum are continually performing slight movements to all points of
the compass, like those of climbing plants.

{46} Mr. Herbert Spencer has recently argued ('Principles of
Biology,' 1865, p. 37 et seq.) with much force that there is no
fundamental distinction between the foliar and axial organs of
plants.

{47} Annales des Sc. Nat. 4th series, Bot. tom. vi. 1856, p. 31.

{48} Moquin-Tandon (Elements de Teratologie. 1841, p. 156) gives the
case of a monstrous bean, in which a case of compensation of this
nature was suddenly effected; for the leaves completely disappeared
and the stipules grew to an enormous size.

Copyright (c) 2007. fullstories.net. All rights reserved.