30 DROSERA ROTUNDIFOLIA. (Cuar. ID. 
bristle. This was done as quickly as possible, but with force 
sufficient to bend the tentacles ; yet only six of them became 
inflected,—three plainly, and three in a slight degree. In 
order to ascertain whether these tentacles which were not 
affected were in an efficient state, bits of meat were placed 
on ten of them, and they all soon became greatly incurved. 
On the other hand, when a large number of glands were 
struck four, five, or six times with the same force as before, 
a needle or sharp splinter of glass being used, a much larger 
proportion of tentacles became inflected; but the result was 
so uncertain as to seem capricious. For instance, I struck 
in the above manner three glands, which happened to be 
extremely sensitive, and all three were inflected almost as 
quickly as if bits of meat had been placed upon them. On 
another occasion I gave a single forcible touch to a consider- 
able number of glands, and not one moved; but these same 
glands, after an interval of some hours, being touched four 
or five times with a needle, several of the tentacles soon 
became inflected. 
The fact of a single touch or even of two or three touches 
not causing inflection must be of some service to the plant; 
as, during stormy weather, the glands cannot fail to be 
occasionally touched by the tall blades of grass, or by other 
plants growing near; and it would be a great evil if the 
tentacles were thus brought into action, for the act of re- 
expansion takes a considerable time, and until the tentacles 
are re-expanded they cannot catch prey. On the other hand, 
extreme sensitiveness to slight pressure is of the highest 
service to the plant; for, as we have seen, if the delicate 
feet of a minute struggling insect press ever so lightly on 
the surfaces of two or three glands, the tentacles bearing 
these glands soon curl inwards and carry the insect with 
them to the centre, causing, after a time, all the circum- 
ferential tentacles to embrace it. Nevertheless, the move- 
ments of the plant are not perfectly adapted to its require- 
ments; for if a bit of dry moss, peat, or other rubbish, is 
blown on to the disc, as often happens, the tentacles clasp it 
in a useless manner. They soon, however, discover their 
mistake and release such innutritious objects. 
It is also a remarkable fact, that drops of water falling 
from a height, whether under the form of natural or artificial 
rain, do not cause the tentacles to move; yet the drops must 
strike the glands with considerable force, more especially 
