THE SHELL-FISH OF THE COAST. H 



will naturally depend upon the force and quantity of 

 the water ejected. This retrograde motion appears 

 to be the more general form of movement of the 

 animal at such times when it is not actually creep- 

 ing about, head downward, along the oceanic floor, 

 although through a twisting of the funnel, or even 

 by means of the fin attached to the hinder part of 

 the body alone, the animal is enabled to pursue a 

 forward course as well. The funnel also serves as 

 an exit to that very remarkable ink-like substance, 

 known as sepia, or true India ink, which is secreted 

 by a special glandular body (ink-bag) lodged in the 

 body-substance. Most of the cuttle-fishes are pro- 

 vided with this inky material, which, indeed, consti- 

 tutes their principal weapon of defence. Instead of 

 boldly sallying forth to meet their would-be assail- 

 ants, wisdom has guided these animals to avoid their 

 more powerful opponents, which they do by cloud- 

 ing the waters with a heavy discharge of sepia. 

 Under cover of the darkness thus produced they 

 generally manage to escape. The effect of the 

 sepia-discharge not only suffices to discourage 

 the enemy, but frequently from its copiousness 

 proves deadly to it. I well remember my first 

 dredging exploits in the Bay of liTaples, when, flushed 

 with the excitement attending a rare capture, I un- 

 guardedly dropped a cuttle-fish into a tub contain- 

 ing my choicest specimens from the deep. In an 

 instant the vision of sea-horses, star-fishes, sea- 

 anemones, etc., faded off into a cloud of increasing 

 blackness, through which no beam of life again 

 penetrated to the surface. 



