NATURE oe Fes 
which are endowed with the property of contracting when stimu- 
lated—viz., nerve and muscle—this property is associated with 
the existence of voltaic currents which have definite directions 
} the tissue. These currents have been the subject of very 
“careful observation by physiologists. They require delicate in- 
struments for their investigation, but the phenomena dependent 
_ on them admit of the application of the most exact measure- 
ments. The constant current which can be shown to exist in a 
_ muscle is called the normal current. The most important fact with 
reference to it is that it exists only so long as the muscle is alive, 
_ and that it ceases during the moment that the muscle is thrown 
| into action. Other characteristics of the muscle currents were 
referred to, which we have not space to mention, 
In certain plants said to possess the property of irritability, 
contraction of certain organs on irritation occur which strikingly 
_ suggest a correspondence of function between them and the 
motor organs of animals. Among the most remarkable are 
_ those of Drosera and some other plants belonging to the same 
natural order, particularly the well-known Venus’ Flytrap 
(Dionza muscipula). The Sensitive Plant, the Common Monkey 
_ Flower, the Rock Cistus, afford other examples. 
| ___ Strange as it may seem the question whether these contractile 
i. moyements are accompanied with the same electrical changes as 
' those which occur in the contraction of muscle and in the 
functional excitation of nerve has never yet been investigated by 
vegetable physiologists. Mr. Darwin, who for many years has 
| _ devoted much attention to the animal-like functions of Dionza 
_ and Drosera, kindly furnished plants for the purpose of the 
"necessary experiments, which have been made by Dr. Sanderson 
_ inthe laboratory of University College, London. The result 
has been that the anticipations he had formed have been con- 
a firmed as to the existence of voltaic currents in these parts, and 
particularly in the leaf of Dionzea. By a most remarkable series 
of experiments (which will be published subsequently) made with 
the aid of Sir W. Thompson's galvanometer, he has shown that 
' these currents are subject, in all respects in which they have been 
_ as yet investigated, to the same laws as those of muscle and 
nerve, 
On Physiological Researches on the Nature of Cholera, by Dr. 
Brunton. 
Without entering into the question of the nature of cholera 
poison, the writer regarded it as probable that its effects might 
be counteracted in the same way as those of other poisons—by 
appropriate antidotes. He supposed that if a poison could be 
found having a similar action to that of cholera, an antidote to 
_ the former might prove a remedy for the latter. The condition 
of cholera collapse has been attributed by Parkes and Johnson 
- to contraction of the vessels in the lungs, and their theory is 
_ generally adopted. The writer fround that muscarin—an alkaloid 
derived from a species of poisonous mushroom—caused contrac- 
tion of the vessels of the lungs and some of the symptoms which 
are counteracted by atropia. It therefore seems probable that 
atropia might be useful in cholera, and in fact an American 
practitioner has recently employed large doses of it with success. 
The fact that nitrate of amyl, which also relaxes the pulmonary 
vessels, is useless as a remedy in cholera, as well as the absence 
of distension of the right side of the heart in cholera patients 
during life, shows that Parkes and Johnson’s theory is imperfect, 
and that one of the most important conditions in cholera is 
active dilatation of the large veins in the interior of the body. 
The condition might be relieved by digitalis. The effect of this 
poison was at once observed in cholera. The rice water stools 
in cholera were stated to have exactly the same composition as 
the fluid secreted after the division of the intestinal nerves in 
Moreau’s experiment, and the profuse secretion from the intes- 
tines in cholera was therefore attributed to paralysis of some of 
the intestinal nerves, Injection of Epsom salts into the intes- 
tines also produced a profuse secretion, though this might be due 
to irritation and not to paralysis of the nerves. This is not les- 
sened in the least by atropia, and it seems therefore probable 
that atropia will not prove a perfect remedy for cholera. Dr. 
Brunton is still endeavouring to find a remedy which will arrest 
this secretion, 
a ee = 
On the Movements of the Glands of Drosera, by Alfred W. 
Bennett, F.L.S. 
The peculiar movement of the glands which cover the margin 
and the upper side of the leaf of the Sundew has often attracted 
the attention of botanists. The observations were all made on 
the commonest species, Drosera. rotundifolia. 
It should be noted in the first place that the glands of Drosera 
are in no sense hairs, z.e, cellular expansions of the epidermis 
of the leaf. They have been shown by Groenland and Trécul 
to be an integral part of the leaf itself, penetrated by a fibro- 
vascular bundle with spiral threads (in other words by a vein or 
nerve of the leaf) from one end to the other, and even furnished 
with stomata on their surface. They terminate in a pellucid 
knob within which is found their peculiar viscid secretion. 
Under low magnifying power this secretion may be seen col- 
lected ubout the knobs, and stretching in thin glutinous strings 
from one to another. The secretion has probably an attraction 
for flies and other small insects, as, if the plant is examined in 
its native bogs scarcely a leaf will be found in which an insect 
is not imprisoned, and one leaf will very often show as many 
as three or four. The experiment was made of placing a very 
small insect, a species of Thrips, ona leaf at that time quite 
unencumbered beneath a low power of the microscope. Im- 
mediately on coming into contact with the viscid secretion 
it made vigorous efforts to escape, but these efforts only seemed 
to entangle it all the more deeply. The contact of the insect ap- 
peared to excite a stronger flow of the secretion, which soon en- 
veloped the body of the animal in a dense almost transparent slime, 
firmly glueing down the wings, and rendering escape hopeless. 
It still, however, continued its struggles, a motion of the legs 
being still clearly perceptible after the lapse of three hours. 
During all this time the insect was sinking lower and lower down 
among the glands towards the surface of the leaf, but only a 
slight change had taken place in the position of the glands 
themselves, which had slightly converged so as to imprison it 
more completely. But afier the struggles of the prisoner had 
ceased, a remarkable change took place in the leaf. Almost the 
whole of the glands on its surface and its margin, even those re- 
moved from the body of the insect by a distance of at least 
double its own length, began to bend over, and point the knobs 
at their extremities towards it, though it was not observed that 
this was accompanied by any increased flow of the secretion from 
them. The experiment was made in the evening; and by the 
next morning almost every gland of the leaf was pointing to- 
wards the object in the centre, forming a dense mass over it. 
The sides of the leaf had also slightly curved forwards so as to 
render the leaf itself more concave. The nearly allied Venus’s 
Fly-trap, or Dioneza muscipula of the United States, which im- 
prisons flies by a much more sudden motion of the sides 
of the leaf, collapsing when irritated on the upper surface, 
is said to digest and absolutely consume the insects thus en- 
trapped. What becomes eventually of the prisoners of the sun- 
dew, my experiments have not been carried sufficiently far to ascer~ 
tain. It will be seen that the most singular feature in the pheno- 
mena here described is that the motion of the greater number of 
the’glands did not begin till after the insect had become compara- 
tively motionless ; and therefore it is very difficult to attribute it 
to the excitement caused by the struggles on any ‘‘contractile 
tissue” at the base of the glands, an explanation which has been 
offered for the sudden and rapid motions of the stamens of 
Berheris or the leaves of Mimosa. It is also quite certain that 
the impinging of raindrops on the surface of the leaf causes no 
similar motion, a peculiarity similar to that which Darwin 
has observed in the case of the motions of tendrils and 
of climbing stems. In order to determine what share 
in these motions of the glands was due to the organic nature of 
the substance imprisoned, and to its power of motion, the fol- 
lowing experiments were also made :—A small piece of raw 
meat was placed on another leaf similar to the first. No imme- 
diate change was observable, and no increased flow of the se- 
cretion ; but after the lapse of a few hours a perceptible inclina- 
tion of the more distant glands towards the object took place. 
The next morning the piece of meat was found, like the fly, 
sunk down on to the surface of the leaf, with almost the whole 
of the glands converging towards'it and above it in just the same 
manner. The changes here were therefore perfectly of the same 
kind as in the case of the fly, though apparently somewhat 
slower. After the lapse of twenty-four hours the piece of mest 
appeared decidedly lighter in colour ; but an accident prevented 
the process of digestion being further traced. On other leayes 
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