Ouay. 11, INFLECTION INDINECTLY CAUSED. 19 
CHAPTER IL 
Tue Movements OF THE TENTACLES FROM THE ConTAcT oF SoLip 
Bones. 
Inflection of the exterior tentacles owing to the glands of the dise 
being excited by repeated touches, or by objects left in contact 
with them— Difference in the action of bodies yielding and not 
yielding soluble nitrogenous matter —Inflection of the exterior 
tentacles directly caused by objects left in contact with their 
glands — Periods of commencing inflection and of subsequent re- 
expansion — Extreme minuteness of the particles causing inflection 
- —Action under water — Inflection of the exterior tentacles when 
their glands are excited by repeated touches— Falling drops of 
water do not cause inflection. 
T wiLu give in this and the following chapters some of 
the many experiments made, which best illustrate the 
manner and rate of movement of the tentacles, when 
excited in various ways. The glands alone in all 
ordinary cases are susceptible to excitement. When 
excited, they do not themselves move or change form, 
but transmit a motor impulse to the bending part of 
their own and adjoining tentacles, and are thus carried 
towards the centre of the leaf. Strictly speaking, the 
glands ought to be called irritable, as the term sensi- 
tive generally implies consciousness; but no one sup- 
poses that the Sensitive-plant is conscious, and as I 
have found the term convenient, I shall use it without 
seruple. I will commence with the movements of the 
exterior tentacles, when indirectly excited by stimulants 
applied to the glands of the short tentacles on the disc. 
The exterior tentacles may be said in this case to be 
indirectly excited, because their own glands are not 
directly acted on. The stimulus proceeding from the 
glands of the disc acts on the bending part of the 
