34 DROSERA ROTUNDIFULIA. Cuar. IL 
The Inflection of the Exterior Tentacles, when their Glands 
are excited by Repeated Touches. 
We have already seen that, if the central glands 
are excited by being gently brushed, they trans- 
mit a motor impulse to the exterior tentacles, 
causing them to bend; and we have now to con- 
sider the effects which follow from the glands of 
the exterior tentacles being themselves touched. On 
several occasions, a large number of glands were 
touched only once with a needle or fine brush, 
hard enough to bend the whole flexible tentacle; 
and though this must have caused a thousand- 
fold greater pressure than the weight of the above 
described particles, not a tentacle moved. On 
another occasion forty-five glands on eleven leaves 
were touched once, twice, or even thrice, with a 
needle or stiff bristle. This was done as quickly as 
possible, but with force sufficient to bend the ten- 
tacles ; 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 te 
be extremely sensitive, and all three were inflected 
almost as quickly as if bits of meat had been placed 
on them. On another occasion I gave a single for- 
