Cuar. X. TRANSMISSION OF MOTOR IMPULSE. 241 
bending of the tentacle; and it appears to be dis- 
charged at first with much greater force than after- 
wards. Thus, in the case above given of a small fly 
naturally caught by a few glands on one side of a leaf, 
an impulse was slowly transmitted from them across 
the whole breadth of the leaf, causing the opposite 
tentacles to be temporarily inflected, but the glands 
which remained in contact with the insect, though 
they continued for several days to send an impulse 
down their own pedicels to the bending place, did 
not prevent the tentacles on the opposite side from 
quickly re-expanding; so that.the motor discharge 
must at first have been more powerful than afterwards. 
When an object of any kind is placed on the disc, 
and the surrounding tentacles are inflected, their 
glands secrete more copiously and the secretion 
becomes acid, so that some influence is sent to 
them from the discal glands. This change in the 
nature and amount of the secretion cannot depend 
on the bending of the tentacles, as the glands of the 
short central tentacles secrete acid when an object is 
placed on them, though they do not themselves bend. 
Therefore I inferred that the glands of the disc sent 
some influence up the surrounding tentacles to their 
glands, and that these reflected back a motor impulse 
to their basal parts; but this view was soon proved 
erroneous. It was found by many trials that tentacles 
with their glands closely cut off by sharp scissors 
often become inflected and again re-expand, still 
appearing healthy. One which was observed con- 
tinued healthy for ten days after the operation. I 
therefore cut the glands off twenty-five tentacles, 
at different times and on different leaves, and seven- 
teen of these soon became inflected, and afterwards 
re-expanded. The re-expansion commenced in about 
