I 
SEA-SLUG AND CUTTLE-FISH 
7 
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 dis¬ 
colouring 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 gray, 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, 1 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. 2 
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 
1 So named according to Patrick Symes’s nomenclature. 
2 See Encyclop. of Anat. and Physiol, article “Cephalopoda.” 
