series: the height of the cliff thus affording a rude measure
of the age.
During our stay, I observed the habits of some marine
animals. A large Aplysia is very common. This sea-slug is
about five inches long; and is of a dirty yellowish colour,
veined with purple. At the anterior extremity, it has tw’o
pair of feelers ; the upper ones of which resemble in shape the
ears of a quadruped. On each side of the lower surface, or
foot, there is a broad membrane, wliich appears sometimes
to act as a ventilator, in causing a current of water to flow
over the dorsal branchiEe. It feeds on delicate sea-w'eeds,
w hich grow’ among the stones in muddy and shallow w’ater;
and I found in its stomach several small pebbles, as in the
gizzards of birds. This slug, w’hen disturbed, emits a very
fine purplish-red fluid, w’hich stains the w’ater for the space
of a foot around. Besides this means of defence, an acrid
secretion, wliich is spread over its body, causes a sharp,
stinging sensation, similar to that produced by the Physalia,
or Portuguese man-of-war.
I was much interested, on several occasions, by w’atching
the habits of an Octopus or cuttle-fish. Although common
in the pools of w’ater left by the retiring tide, these animals
were not easily caught. By means of their long arms and
suckers, they could drag their bodies into very narrow crevices
; and when thus fixed, it required great force to remove
them. At other times they darted tail first, with the rapidity
of an arrow, from one side of the pool to the other, at
the same instant discolouring the water with a dark chestnut-
brow’n ink. These animals also escape detection by a very
extraordinary, chameleon-like, power of changing their colour.
They appear to vary the tints, according to the nature of the
ground over which they p a ss: when in deep water, their
general shade was brownish purple, but w’hen placed on the
land, or in shallow water, this dark tint changed into one of
a yellowish green. The colour, examined more carefully,
was a French gray, w’ith numerous minute spots of bright
yellow: the former of these varied in intensity; the latter
entirely disappeared and appeared again by turns. These
changes W’ere effected in such a manner, that clouds, varj’ing
in tint between a hyacinth red and a chestnut brow’n,* w’ere
continually passing over the body. Any part being subjected
to a slight shock of galvanism, became almost black:
a similar effect, but in a less degree, was produced by
scratcliing the skin with a needle. These clouds, or blushes,
as they may be called, w’hen examined under a glass, are
described as being produced by the alternate expansions and
contractions of minute vesicles, containing variously-coloured
fluids.t
This cuttle-fish displayed its chameleon-like power both
during the act of sw'imming and whilst remaining stationary
at the bottom. I w’as much amused by the various arts to
escape detection used by one individual, which seemed fully
aware that I was watching it. Remaining for a time motionless,
it w’ould then stealthily advance an inch or two, like a
cat after a mouse; sometimes changing its colour: it thus
proceeded, till having gained a deeper part, it darted away,
leaving a dusky train of ink to hide the hole into w'hich
it had crawled.
While looking for marine animals, with my head about
two feet above the rocky shore, I was more than once
saluted by a jet of water, accompanied by a slight grating
noise. At first I did not know what it was, but afterwards I
found out that itw’as the cuttle-fish, which, though concealed
in a hole, thus often led me to its discovery. That it possesses
the power of ejecting w’ater there is no doubt, and it
appeared to me certain that it could, moreover, take good
aim by directing the tube or siphon on the under side of its
body. From the difficulty which these animals have in carrying
their heads, they cannot crawl with ease when placed
on the ground. I observed that one which I kept in the
cabin was slightly phosphorescent in the dark.
S t . P a u l ’s R o c k s .— In crossing the Atlantic w’e hove to,
* So n am e d a c co rd in g to P a t . Symes’s n om e n c la tu r e .
t S e e E n c y c lo . o f A n a t. a n d P h y s io l., a rtic le Cephalopoda.