Cuap. IX] -POISON OF THE COBRA. 169 
of protoplasm were examined after 3 hrs., and again after 7 hrs., and 
on ne other occasion have | seen them undergoing such rapid changes 
of form. After 8 hrs. 30 m. the glands had becume quite white; they 
had not secreted any great quantity of mucus. The leaves were now 
placed in water, and after 40 hre. re-expanded, showing that they were 
not much or at all injured. During their immersion in water the 
protoplasm within the cells of the tentacles was occasionally examined, 
and always found in strong movement. 
Two leaves were next immersed, each in thirty minims of a much 
stronger solution, of one part to 109 of water; so that each received 4 
of a grain, or 16°2 mg. After 1 hr. 45 m. the submarginal tentacles 
were strongly inflected, with the glands somewhat pale; after 3 hrs. 
50 m. both leaves had all their tentacles closely inflected and the 
glands white. Hence the weaker solution, 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 immersion 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 pro- 
toplasm, which had become of a dingy purple, were still in strong 
movement, 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 ex- 
ception here and there of a single globular mass. We thus see how 
completely the protoplasm bad 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 another 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 concerned, 
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 
