visible in the dark and
therefore useless. They have, however, developed a luminous organ, a
living "glow-lamp," at the end of the filament, which doubtless proves a
very effective lure.

In the great depths, however, fish are comparatively rare. Nor are
Molluscs much more abundant. Sea-urchins, Sea Slugs, and Starfish are
more numerous, and on one occasion 20,000 specimens of an Echinus were
brought up at a single haul. True corals are rare, nor are Hydrozoa
frequent, though a giant species, allied to the little Hydra of our
ponds but upwards of 6 feet in height, has more than once been met
with. Sponges are numerous, and often very beautiful. The now well known
Euplectella, "Venus's Flower-basket," resembles an exquisitely delicate
fabric woven in spun silk; it is in the form of a gracefully curved
tube, expanding slightly upwards and ending in an elegant frill. The
wall is formed of parallel bands of glassy siliceous fibres, crossed by
others at right angles, so as to form a square meshed net. These sponges
are anchored on the fine ooze by wisps of glassy filaments, which often
attain a considerable length. Many of these beautiful organisms,
moreover, glow when alive with a soft diffused light, flickering and
sparkling at every touch. What would one not give to be able to wander a
while in these wonderful regions!

It is curious that no plants, so far as we know, grow in the depths of
the Ocean, or, indeed, as far as our present information goes, at a
greater depth than about 100 fathoms.

As regards the nature of the bottom itself, it is in the neighbourhood
of land mainly composed of materials, brought down by rivers or washed
from the shore, coarser near the coast, and tending to become finer and
finer as the distance increases and the water deepens. The bed of the
Atlantic from 400 to 2000 fathoms is covered with an ooze, or very fine
chalky deposit, consisting to a great extent of minute and more or less
broken shells, especially those of Globigerina. At still greater depths
the carbonate of lime gradually disappears, and the bottom consists of
fine red clay, with numerous minute particles, some of volcanic, some of
meteoric, origin, fragments of shooting stars, over 100,000,000 of which
are said to strike the surface of our earth every year. How slow the
process of deposition must be, may be inferred from the fact that the
trawl sometimes brings up many teeth of Sharks and ear-bones of Whales
(in one case no