Chap. IX.] POISON OF THE COBRA. 169 



marginal tentacles were strongly inflected, with the glands some- 

 what pale; after 3 hrs. 30 m. both leaves had all their tentacles 

 closely inflected and the glands white. Hence the weaker solu- 

 tion, as in so many other cases, induced more rapid inflection than 

 the stronger one; but the glands were sooner rendered white by 

 the latter. After an immersion of 24 hrs. some of the tentacles 

 were examined, and the protoplasm, still of a fine purple colour, 

 was found aggregated into chains of small globular masses. These 

 changed their shapes with remarkable quickness. After an im- 

 mersion of 48 hrs. they were again examined, and their movements 

 were so plain that they could easily be seen under a weak power. 

 The leaves were now placed in water, and after 24 hrs. (i. e. 72 

 hrs. from their first immersion) the little masses of protoplasm, 

 which had become of a dingy purple, were still in strong move- 

 ment, changing their shapes, coalescing, and again separating. 



In 8 hrs. after these two leaves had been placed in water (i. e. 

 in 56 hrs. after their immersion in the solution) they began to 

 re-expand, and by the next morning were more expanded. After 

 an additional day (i. e. on the fourth day after their immersion 

 in the solution) they were largely, but not quite fully, expanded. 

 The tentacles were now examined, and the aggregated masses were 

 almost wholly re-dissolved; the cells being filled with homogeneous 

 purple fluid, with the exception here and there of a single globular 

 mass. We thus see how completely the protoplasm had escaped 

 all injury from the poison. As the glands were soon rendered 

 quite white, it occurred to me that their texture might have been 

 modified in such a manner as to prevent the poison passing into 

 the cells beneath, and consequently that the protoplasm within 

 these cells had not been at all affected. Accordingly I placed an- 

 other leaf, which had been immersed for 48 hrs. in the poison and 

 afterwards for 24 hrs. in water, in a little solution of one part of 

 carbonate of ammonia to 218 of water; in 30 m. the protoplasm 

 in the cells beneath the glands became darker, and in the course of 

 24 hrs. the tentacles were filled down to their bases with dark- 

 coloured spherical masses. Hence the glands had not lost their 

 power of absorption, as far as the carbonate of ammonia is con- 

 cerned. 



From these facts it is manifest that the poison of the cobra, 

 though so deadly to animals, is not at all poisonous to Drosera; 

 yet it causes strong and rapid inflection of the tentacles, and soon 

 discharges all colour from the glands. It seems even to act as a 

 stimulant to the protoplasm, for after considerable experience in 

 observing the movements of this substance in Drosera, I have never 

 seen it on any other occasion in so active a state. I was therefore 

 anxious to l^am how this poison affected animal protoplasm ; and 

 Dr. Fayrer w^is so kind as to make some observations for me, which 

 he has since published.* Ciliated epithelium from the mouth of 

 a frog was placed in a solution of .03 gramm to 4.6 cubic cm. of 

 water ; others being placed at the same time in pure water for com- 

 parison. The movements of the cilia in the solution seemed at 



' Proceeding of Royal Society,* Feb. 18, 1875. 



