466 
THE OCEAN WORLD. 
vided with a slightly salient point. The upper part is surrounded 
with a horny or cretaceous margin, and presents in the centre a 
combination of spongy cells. 
Most of the Cephalopoda secrete a 
blackish, inky fluid, to which some all 11 ' 
sion has been made, but the uses of which, 
in the economy of the animals, is imp er ' 
fectly known. The cuttles have consider' 
able quantities of this liquor, which lS 
contained in a sort of sac or ink-purse, 
placed low down in the abdomen. Wh en 
the animal is pursued or threatened with 
danger it discharges a jet of the fl nlC ’ 
which renders the water thick and muddy, 
and permits it to escape in the obscurity 
from its pursuers. It appears that tb 0 
cuttle-fish avails itself of this stratagc® 
when left accidentally ashore. I* 5 . 19 
related of an English officer that, having 
dressed for dinner, and having some tim e 
to spare, he proceeded along the shore on his favourite search 
objects of natural history. He reached a hollow rock in which 8 
cuttle-fish had established its quarters ; he soon detected the ani® 8 > 
which looked at him for some time with its great prominent ey e ® ’ 
in short, they watched each other with fixed attention. This wn 
contemplation came to a sudden and unexpected termination by 1 
discharge of a voluminous jet of inky fluid, which covered the offi cer 
with the black liquid, which was the more unfortunate, since he was 
bis summer dress of white trousers. 
The ink of the cuttle-fish is a favourite pigment, used in wat er . 
colour painting under the name of sepia. It is truly indestructi 
and the hard and black substance found in the sac of fossil s P eC1 ^. ■. 
cuttle-fish when diluted with water produces a brilliant sepia. ^ ^ 
Fig. 324. 
ternal bone of 
Sepia officinalis. 
Fig.325. Sepia tuber- 
culosa (Lamarck). 
in making ink. It was long supposed to be the chief mgreaie 
China ink ; but a recent traveller, Mr. Seebold, who has vis ^ g 
the manufactory, and investigated the subject, has revealed the 
process by which it is prepared. 
