170 DROSERA ROTUNDIFOLIA. [Cuar. IX. 
colour from the glands. It seems even to act as a stimulant to the 
protoplasm, for after considerable experience in observing the move- 
ments of this substance in Drosera, I have never seen it on any other 
occasion in so active a state. I was therefore anxious to learn how 
this poison affected animal protoplasm; and Dr. Fayrer was 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 comparison. The movements of the cilia 
in the solution seemed at first increased; but soon Janguished, and 
after between 15 and 20 minutes ceased; whilst those in the water 
were still acting vigorously. ‘The white corpuscles of the blood of a 
frog, and the cilia on two infusorial animals, a Paramecium and 
Volvox, were similarly affected by the poison. Dr. Fayrer also found 
that the muscle of a frog lost its irritability after an immersion of 
20 m. in the solution not then responding to a strong electrical current. 
On the other hand, the movements of the cilia on the mantle of an 
Unio were not always arrested, even when left for a considerable time 
in a very strong solution. On the whole, it seems that the poison of 
the cobra acts far more injuriously on the protoplasm of the higher 
animals than on that of Drosera. 
There is one other point which may be noticed. I have occasionally 
observed that the drops of secretion round the glands were rendered 
somewhat turbid by certain solutions, and more especially by some 
acids, a film being formed on the surfaces of the drops; but I never 
saw this effect produced in so conspicuous a manner as by the cobra 
poison. When the stronger solution was employed, the drops appeared 
in 10 m. like little white rounded clouds. After 48 hrs. the secretion, 
was changed into threads and sheets of a membranous substance, 
including minute granules of various sizes. 
Camphor.—Some scraped camphor was left for a day in a bottle 
with distilled water, and then filtered. A solution thus made is said 
to contain ~>4,5 of its weight of camphor; it smelt and tasted of this 
substance. ‘len leaves were immersed in this solution; after 15 m. 
five of them were well inflected, two showing a first trace of movement 
in 11 m. and 12 m.; the sixth leaf did not begin to move until 15 m. 
had elapsed, but was fairly well inflected in 17 m. and quite closed in 
24 m.; the seventh began to move in 17 m., and was completely shut 
in 26m. ‘The eighth, ninth, and tenth leaves were old and of a very 
dark red colour, and these were not inflected after an immersion of 
24 hrs.; so that in making experiments with camphor it is necessary 
to avoid such leaves. Some of these leaves, on being left in the 
solution for 4 hrs., became of a rather dingy pink colour, and secreted 
much mucus; although their tentacles were closely inflected, the 
protoplasm within the cells was not at all aggregated. On another 
* ©Proceedings of Royal Society,’ Feb. 18, 1875. 
