somewhat
pointed at the
apex, and blunt
at the base
of the Ash, 48.5 ... 51.5
the thick basal
end often drawn
in to serve as
food
of Robinia, 44 ... 56
extremely thin,
especially
towards the
apex, so as to
be ill-fitted
for plugging up
the burrows
Triangles of 62 15 23
paper, of the
two sizes
of the broad 59 25 16
ones alone
of the narrow 65 14 21
ones alone
If we consider these several cases, we can hardly escape from the
conclusion that worms show some degree of intelligence in their manner of
plugging up their burrows. Each particular object is seized in too
uniform a manner, and from causes which we can generally understand, for
the result to be attributed to mere chance. That every object has not
been drawn in by its pointed end, may be accounted for by labour having
been saved through some being inserted by their broader or thicker ends.
No doubt worms are led by instinct to plug up their burrows; and it might
have been expected that they would have been led by instinct how best to
act in each particular case, independently of intelligence. We see how
difficult it is to judge whether intelligence comes into play, for even
plants might sometimes be thought to be thus directed; for instance when
displaced leaves re-direct their upper surfaces towards the light by
extremely complicated movements and by the shortest course. With
animals, actions appearing due to intelligence may be performed through
43