10 DROSERA ROTUNDIFOLIA. (Cuar. I. 
The kind of inflection which the tentacles undergo is best 
shown when the gland of one of the long exterior tentacles 
is in any way excited; for the surrounding ones remain 
unaffected. In the accompanying outline (fig. 6) we sce one 
tentacle, on which a particle of meat had been placed, thus 
bent towards the centre of the leaf, with two others retaining 
their original position. A gland may be excited by being 
simply touched three or four times, or by prolonged contact 
with organic or inorganic objects, and various fluids. I have 
distinctly seen, through a lens, a tentacle beginning to bend 
in ten seconds, after an object had been placed on its gland; 
and I have often seen strongly pronounced inflection in under 
one minute. It is surprising how minute a particle of any 
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Frc. 6, 
(Drosera rotundifolia.) 
Diagram showing one of the exterior tentacles closely inflected; the two adjoining 
ones in their ordinary position. 
substance, such as a bit of thread or hair or splinter of glass, 
if placed in actual contact with the surface of a gland, 
suffices to cause the tentacle to bend. If the object, which 
has been carried by this movement to the centre, be not very 
small, or if it contains soluble nitrogenous matter, it acts on 
the central glands; and these transmit a motor impulse to 
the exterior tentacles, causing them to bend inwards. 
Not only the tentacles, but the blade of the leaf often, 
but by no means always, becomes much incurved, when any 
strongly exciting substance or fluid is placed on the disc. 
Drops of milk and of a solution of nitrate of ammonia or soda 
are particularly apt to produce this effect. The blade is thus 
converted into a little cup. The manner in which it bends 
