nted by climbing plants of such extraordinary dimensions
that many of them exceed in diameter the girth of a man; and these
gigantic appendages are to be seen surmounting the tallest trees in the
forest, grasping their stems in firm convolutions, and then flinging
their monstrous tendrils over the larger limbs till they reach the top,
whence they descend to the ground in huge festoons, and, after including
another and another tree in their successive toils, they once more
ascend to the summit, and wind the whole into a maze of living network
as massy as if formed by the cable of a line-of-battle ship. When, by
and by, the trees on which this singular fabric has become suspended
give way under its weight, or sink by their own decay, the fallen trunk
speedily disappears, while the convolutions of climbers continue to grow
on, exhibiting one of the most marvellous and peculiar living mounds of
confusion that it is possible to fancy. Frequently one of these creepers
may be seen holding by one extremity the summit of a tall tree, and
grasping with the other an object at some distance near the earth,
between which it is strained as tight and straight as if hauled over a
block. In all probability the young tendril had been originally fixed in
this position by the wind, and retained in it till it had gained its
maturity, where it has the appearance of having been artificially
arranged as if to support a falling tree."[229]

Leaving the vegetable world, we may find some very curious examples of
parasitism among Insects. Every one who has paid the slightest attention
to this class of animals is aware that there are slender flies called
_Ichneumons_, whose grubs are hatched and reared in the bodies of other
insects. Many of these have the ovipositor greatly lengthened, and
projecting like a very slender needle from the extremity of the abdomen.
In some species, this needle-like organ is three or four times the
entire length of the body; and this great longitude is intended to reach
the pupae of wasps and similar insects which inhabit deep holes. The
needle itself is well worthy of study. It is not simple, but composed
of two pieces forming a sheath, which open and reveal a central finer
filament, furnished at its tip (in _Pimpla manifestator_, for example)
with saw-like teeth. With this instrument, which possesses great
elasticity and flexibility, the insect works, as a carpenter with his
brad-awl, boring through the clay, with whi