Cuar. X.]) DIRECTION OF INFLECTED TENTACLES. 199 
was wonderful; so that in some cases I could detect no 
deviation from perfect accuracy. Thus, although the short 
tentacles in the middle of the disc do not bend when their 
glands are excited in a direct manner, yet if they receive 
a motor impulse from a point on one side, they direct them- 
selves to the point equally well with the tentacles on the 
borders of the disc. 
In these experiments, some of the short tentacles on the 
disc, which would have been directed to the centre, had the 
leaf been immersed in an exciting fluid, were now inflected in 
an exactly opposite direction, viz. towards the circumference. 
These tentacles, therefore, had deviated as much as 180° 
from the direction which they would have assumed if their 
own glands had been stimulated, and which may be 
considered as the normal one. Between this, the greatest 
possible and no deviation from the normal direction, every 
degree could be observed in the tentacles on these several 
leaves. Notwithstanding the precision with which the ten- 
tacles generally were directed, those near the circumference 
of one leaf were not accurately directed towards some phos- 
phate of lime at a rather distant point on the opposite side of 
the disc. It appeared as if the motor impulse in passing 
transversely across nearly the whole width of the disc had 
departed somewhat from a true course. This accords with 
what we have already seen of the impulse travelling less 
readily in a transverse than in a longitudinal direction. In 
some other cases, the exterior tentacles did not seem capable 
of such accurate movement as the shorter and more central 
ones. 
Nothing could be more striking than the appearance 
of the above four leaves, each with their tentacles pointing 
truly to the two little masses of the phosphate on their discs. 
We might imagine that we were looking at a lowly organised 
animal seizing prey with its arms. In the case of Drosera 
the explanation of this accurate power of movement, no 
doubt, lies in the motor impulse radiating in all directions, 
and whichever side of a tentacle it first strikes, that side 
contracts, and the tentacle consequently bends towards the 
point of excitement. The pedicels of the tentacles are 
flattened, or elliptic in section. Near the bases of the short 
central tentacles, the flattened or broad face is formed of 
about five longitudinal rows of cells; in the outer tentacles 
of the disc, it consists of about six or seven rows; and in 
