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PROGRESS OF MICROSCOPICAL SCIENCE. 
treated with water, the other with the poisoned solution. At 2.10 p.m. 
ciliary motion vigorous in both, perhaps more so in that subjected to 
the poisoned solution. 2.18. Non-poisoned cilia active. Poisoned 
cilia very feeble. 2.20. Non-poisoned cilia still active. Poisoned 
cilia very feeble. 2.24. Non-poisoned cilia active. Poisoned cilia 
very languid. 2.30. Non-poisoned cilia still active. Poisoned cilia 
have entirely ceased to act. It is evident from this that the poison 
first stimulates and then destroys the activity of the ciliary action. 
August 14. — Frog’s blood placed in salt solution, '75 per cent., at 
1.25 p.m. on warm stage, and then subjected to the action of cobra- 
poison. At first the amoeboid movements of white corpuscles went 
on vigorously. At 2 p.m. they had ceased, or very nearly so, in all 
that appeared in the field. 2.30. All movement had entirely ceased. 
The red corpuscles seemed more flattened, the nucleus more visible, 
and the edges better defined, assuming a pointed and more oval form 
than usual. 
August 25. — Newts’ blood examined under -|4h object-glass on 
hot stage, white corpuscles moving slowly. Cobra-poison applied, 
but no perceptible change observed. The following communications 
were received from Mr. C. Darwin on the action of some of the same 
cobra-poison on vegetable protoplasm : — “ You will perhaps like to 
hear how it acted on Drosera. I made a solution of ^ gr. to 5ij of 
water. A minute drop on a small pin’s head acted powerfully on 
several glands, more powerfully than the fresh poison from an adder’s 
fang. I also immersed three leaves in 90 minims of the solution ; 
the tentacles soon became inflated and the glands quite white, as if 
they had been placed in boiling water. I felt sure that the leaves 
were killed ; but after eight hours’ immersion they were placed in 
water, and after about forty-eight hours re-expanded, showing that 
they were by no means killed. The most surprising circumstance is, 
that, after an immersion of forty-eight hours, the protoplasm in the 
cells was in unusually active movement. Now, can you inform me 
whether this poison, if diluted, arrests the movement of vibratile 
cilia ? I dissolved i gr. [of cobra-poisonj in sj of water, so that I 
was able to immerse two leaves: It acted as before, but more ener- 
getically ; and I observed more clearly, this time, that the solution 
makes the secretion round the glands cloudy, which I have never 
before observed. But here comes the remarkable point; after an 
immersion of forty-eight hours, the protoplasm within the cells in- 
cessantly changes form, and I never saw it on any other occasion so 
active. Hence I cannot doubt that this poison is a stimulant to the 
protoplasm ; and I shall be very curious to find out in your papers 
whether you have tried its action on the cilia and on the colourless 
corpuscles of the blood. If the poison does arrest their movement, it 
will show that there is a profound difference between the protoplasm 
of animals and of this plant. Therefore if you try any further 
experiments I hope that you will be so kind as to inform me of the 
results. I may add that I tried at first 1 gr. to the 5J, as that is my 
standard strength for all substances. It is certainly very remarkable 
that the poison should act so differently on the cilia and on the pro- 
oplasm of Drosera. After the forty-eight hours’ immersion, I placed 
