"THE VOYAGE OF THE BEAGLE" - читать интересную книгу автора (Darwin Charles)

sea-weeds which grow among the stones in muddy and shallow
water; and I found in its stomach several small pebbles,
as in the gizzard of a bird. This slug, when disturbed, emits
a very fine purplish-red fluid, which stains the water for the
space of a foot around. Besides this means of defence, an
acrid secretion, which 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 watching
the habits of an Octopus, or cuttle-fish. Although common
in the pools of water 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-brown
ink. These animals also escape detection by a very
extraordinary, chameleon-like power of changing their colour.
They appear to vary their tints according to the nature
of the ground over which they pass: when in deep water,
their general shade was brownish purple, but when 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 grey, with numerous minute spots of bright
yellow: the former of these varied in intensity; the latter
entirely disappeared and appeared again by turns. These
changes were effected in such a manner, that clouds, varying
in tint between a hyacinth red and a chestnut-brown, [4] were
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 scratching
the skin with a needle. These clouds, or blushes as they may
be called, are said to be produced by the alternate expansion
and contraction of minute vesicles containing variously
coloured fluids. [5]

This cuttle-fish displayed its chameleon-like power both
during the act of swimming and whilst remaining stationary
at the bottom. I was 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 would 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 which it
had crawled.

While looking for marine animals, with my head about