ON THE NERVOUS SYSTEM OF VEGETABLES. 
07 
ON “THE NERVOUS SYSTEM OF VEGETABLES.— 
DO PLANTS FEEL?”* 
BY F. T. MOTT, F.R.G.S. 
It is well known that many plants possess, 
in some of their organs and tissues, a certain 
irritability by which various functional move¬ 
ments are set up and regulated. The folding- 
leaves of sensitive plants, of which there are 
many; the sleep of plants, the twisting- 
petioles and tendrils of climbers, the fly-traps 
of Drosera and Dionaea, the sensitive anthers of the Barberry, 
are familiar examples of this irritability which induces 
motion. But how is the motion produced ? and what is the 
fundamental cause concealed under the term “ irritability”? 
These movements, which are all curvilinear, and represent 
the bending of some organ to one side, may arise either from 
the contraction of tissue on the inner side or from its 
expansion on the outer side. In the common sensitive-plant 
it is believed by Sachs that the leaf movements are caused 
by a sudden rush of liquid from the cells on one side of the 
articulation to those of the other side, which become at once 
turgid and enlarged, and bend the leaf over towards the 
empty cells. But in curving stems and tendrils Asa Gray 
has shown that if a slice is cut oft* the convex side, so as to 
make it thinner, the bending is more rapid, which shows that 
it is due to the contractions of cells on the inner side, not to 
the expansion of those on the outer. 
Here, then, is something approaching to true contractile 
tissue, that tissue which constitutes the active muscles in the 
higher animals. But such animal muscle contracts only at 
the bidding of some delicate nerve fibre, and no such fibre 
has anywhere been found in the Vegetable Kingdom. 
There are, however, among the lowest orders of animal 
life many examples of a contractile tissue which operates in 
the same manner as the muscles of the higher animals, and 
yet is not controlled by any discoverable system of nerve 
fibres. The Amaeba has no nerves, yet it moves about 
apparently at its own will. The Medusae swim by contractions 
of the gelatinous bell, and according to Mr. G. J. Romanes 
irritation is conveyed from side to side of this bell, yet no 
trace of nerve fibre can be found in it. 
Surely, then, we may be justified in attributing the 
contraction of vegetable tissue to a power the same as, or 
* Transactions of Section D of the Leicester Literary and 
Philosophical Society- Read June 20th, 1883. 
