AS COMPARED WITH THAT OF OTHER VENOMOUS SNAKES. 127 



Experiment XXIII. 



August 14th. — Frog's blood placed in salt solution, 0*75 per 

 cent., at 1.25 p.m. on warm stage, and then subjected to the 

 action of cobra-poison. 



At first the amceboid 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. 



P^xperiment XXIV. 



August 25th, 1874. — Newts' blood examined under ^ 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 ou 

 vegetable protoplasm : — 



" You will perhaps like to hear how it acted on Brosera. 1 

 made a solution of ^ gr. to 5ij. of water. A minute drop on a 

 small pin's head acted powerfully on several glands, more power- 

 fully 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 48 hours re-expanded, 

 showing that they were by no means killed. The most sur- 

 prising circumstance is that, after an immersion of 48 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 J gr. [of cobra-poison] in 5J of water, so that I 

 was able to immerse two leaves. It acted as before, but more 

 energetically ; 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 



