ll employed, it made use of them on
a different principle. Around the circular rim of each there is a fringe
of minute thorns, hooked somewhat like those of the wild rose. In
clinging to the hard polished pebbles, these were overlapped by a fleshy
membrane, much in the manner that the cushions of a cat's paw overlap
its claws when the animal is in a state of tranquillity; and by means of
the projecting membrane, the hollow interior was rendered air-tight, and
the vacuum completed: but in dealing with the hand--a soft
substance--the thorns were laid bare, like the claws of a cat when
stretched out in anger, and at least a thousand minute prickles were
fixed in the skin at once. They failed to penetrate it, for they were
short, and individually not strong; but, acting together by hundreds,
they took at least a very firm hold.

What follows may be deemed barbarous; but the men who gulp down at a
sitting half-a-hundred live oysters to gratify their taste, may surely
forgive me the destruction of a single mollusc to gratify my curiosity!
I cut open the sack of the creature with a sharp penknife, and laid bare
the viscera. What a sight for Harvey, when prosecuting, in the earlier
stages, his grand discovery of the circulation! _There_, in the centre,
was the yellow muscular heart, propelling into the transparent, tubular
arteries, the _yellow_ blood. Beat--beat--beat:--I could see the whole
as in a glass model; and all I lacked were powers of vision nice enough
to enable me to detect the fluid passing through the minuter arterial
branches, and then returning by the veins to the _two_ other hearts of
the creature; for, strange to say, it is furnished with three. There in
the midst I saw the yellow heart, and, lying altogether detached from
it, two other deep-coloured hearts at the sides. I cut a little deeper.
_There_ was the gizzard-like stomach, filled with fragments of minute
mussel and crab shells; and _there_, inserted in the spongy, conical,
yellowish-coloured liver, and somewhat resembling in form a Florence
flask, was the ink-bag distended, with its deep dark sepia--the
identical pigment sold under that name in our colour shops, and so
extensively used in landscape drawing by the limner. I then dissected
and laid open the circular or ring-like brain that surrounds the
creature's parrot-like beak, as if its _thinking_ part had no other
vocation than simply to take care of the mouth and its
pertinents--almost the sole em