closely inflected. Fragments of flies were placed on the glands of four
of the outer tentacles, extended in the same plane with that of the
blade, and three of these fragments were carried in 35 m. through an
angle of 180o to the centre. The fragment on the fourth tentacle was
very minute, and it was not carried to the centre until 3 hrs. had
elapsed. In three other cases minute flies or portions of larger ones
were carried to the centre in 1 hr. 30 s. In these seven cases, the
fragments or small flies, which had been carried by a single tentacle
to the central glands, were well embraced by the other tentacles after
an interval of from 4 to 10 hrs.
I also placed in the manner just described six small balls of
writing-paper (rolled up by the aid of pincers, so that they were not
touched by my fingers) on the glands of six exterior tentacles on
distinct leaves; three of these were carried to the centre in about 1
hr., and the other three in rather more than 4 hrs.; but after 24 hrs.
only two of the six balls were well embraced by the other tentacles. It
is possible that the secretion may have dissolved a trace of glue or
animalised matter from the balls of paper. Four particles of
coal-cinder were then placed on the glands of four exterior tentacles;
one of these reached the centre in 3 hrs. 40 m.; the second in 9 hrs.;
the third within 24 hrs., but had moved only part of the way in 9 hrs.;
whilst the fourth moved only a very short distance in 24 hrs., and
never moved any farther. Of the above three bits of cinder which were
ultimately carried to the centre, one alone was well embraced by [page
26] many of the other tentacles. We here see clearly that such bodies
as particles of cinder or little balls of paper, after being carried by
the tentacles to the central glands, act very differently from
fragments of flies, in causing the movement of the surrounding
tentacles.
I made, without carefully recording the times of movement, many similar
trials with other substances, such as splinters of white and blue
glass, particles of cork, minute bits of gold-leaf, &c.; and the
proportional number of cases varied much in which the tentacles reached
the centre, or moved only slightly, or not at all. One evening,
particles of glass and cork, rather larger than those usually employed,
were placed on about a dozen glands, and next morning, after 13 hrs.,
every single tentacle had carried its little load to the centre; but
the unusually large size of the particles will account for this result.
25