causing them to secrete more copiously, and the secretion to become
acid. This latter fact is, I believe, quite new in the physiology of
plants; it has indeed only recently been established that in the animal
kingdom an influence can be transmitted along the nerves to glands,
modifying their power of secretion, independently of the state of the
blood-vessels.

The Inflection of the Exterior Tentacles from the Glands of the Disc
being excited by Repeated Touches, or by Objects left in Contact with
them.

The central glands of a leaf were irritated with a small stiff
camel-hair brush, and in 70 m. (minutes) several of the outer
tentacles were inflected; in 5 hrs. (hours) all the sub-marginal
tentacles were inflected; next morning after an interval of about 22
hrs. they were fully re-expanded. In all the following cases the period
is reckoned from the time of first irritation. Another leaf treated in
the same manner had a few tentacles inflected in 20 m.; in 4 hrs. all
the submarginal and some of the extreme marginal tentacles, as well as
the edge of the leaf itself, were inflected; in 17 hrs. they had
recovered their proper, expanded position. I then put a dead fly in the
centre of the last-mentioned leaf, and next morning it was closely
clasped; five days afterwards the leaf re-expanded, and the tentacles,
with their glands surrounded by secretion, were ready to act again.

Particles of meat, dead flies, bits of paper, wood, dried moss, sponge,
cinders, glass, &c., were repeatedly [page 21] placed on leaves, and
these objects were well embraced in various periods from one hr. to as
long as 24 hrs., and set free again, with the leaf fully re-expanded,
in from one or two, to seven or even ten days, according to the nature