264. DROSERA ROTUNDIFOLIA. Cuar. XI. 
though with ccnsiderable force and with a hard object, 
the tentacle doesnot bend. The plant is thus saved 
from much useless movement, as during a high wind 
the glands can hardly escape being occasionally 
brushed by the leaves of surrounding plants. Though 
insensible to a single touch, they are exquisitely sensi- 
tive, as just stated, to the slightest pressure if pro- 
longed for a few seconds; and this capacity is mani- 
festly of service to the plant in capturing small 
insects. Even gnats, if they rest on the glands with 
their delicate feet, are quickly and securely embraced. 
The glands are insensible to the weight and repeated 
blows of drops of heavy rain, and the plants are thus 
likewise saved from much useless movement. 
The description of the movements of the tentacles 
was interrupted in the third chapter for the sake of 
describing the process of aggregation. This process 
always commences in the cells of the glands, the con- 
tents of which first become cloudy; and this has 
been observed within 10 s. after a gland has been 
excited. Granules just resolvable under a very high 
power soon appear, sometimes within a minute, in the 
cells beneath the glands; and these then aggregate 
into minute spheres. The process afterwards travels 
down the tentacles, being arrested for a short time at 
each transverse partition. The small spheres coalesce 
into larger spheres, or into oval, club-headed, thread- 
or necklace-like, or otherwise shaped masses of proto- 
plasm, which, suspended in almost colourless fluid, 
exhibit incessant spontaneous changes of form. These 
frequently coalesce and again separate. If a gland 
has been powerfully excited, all the cells down to the 
base of the tentacle are affected. In cells, especially 
if filled with dark red fluid, the first step in the 
a 
