Oct. 1, 1869.] 



HARDWICKE'S SCIENCE-GOSSIP. 



219 



In order to swim, the animal swells out the cloak 

 in front, so that the water flows in between it and 

 the body. Then it closes the cloak tightly about 

 the neck, so that the only way the water can get 

 out is through the siphon. Then it contracts very 

 forcibly its coat, which, it must be remembered, is 

 a part of the animal, and the water is driven out in 

 a jet from the siphon under the throat, and the 

 body is propelled in the opposite direction ; that is, 

 backward, like a rocket through the water. This 



Fig. 1 68. Sepia officinalis. 



Fig. 169. 

 Internal bone of Sepia. 



top of the waves, seated in her boat-like shell, and 

 spreading her broad arms to the winds for sails. 

 But unfortunately the story has no foundation in 

 fact. She either crawls about on the bottom of the 

 sea, or swims quite like any other cuttle-fish, shell 

 foremost, only occasionally coming to the surface. 

 Strangely enough, she holds the two broad hand-like 



siphon is flexible like a water-hose, and can be 

 bent so as to direct the stream not only forward, 

 but sideways and backward, so that the animal can 

 move in almost any direction, or turn somersaults 

 with perfect ease ; and so rapidly 

 do some cuttle-fishes swim, that 

 they are able to make long leaps 

 out of the water. Usually, how- 

 ever, the animal swims backward, 

 with its long arms trailing behind. 

 Our common cuttle-fish of this 

 coast has, in addition to its eight 

 arms, two long slender tentacles, 

 which may be withdrawn into the 

 body.^ The tail is pointed, and 

 furnished with a fin on each 

 side. 



The Octopods, to which the 

 Brazilian cuttle-fish belongs, 

 have round purse-like bodies, 

 and eight arms united at the 

 base with a web, and they 

 swim by opening and shutting 

 their arms like an umbrella ; in 

 this mode of swimming they resemble the "elly- 

 fishes. 



The paper nautilus is nothing in the world but 

 a female cuttle-fish that builds a shell. There was 

 a very pretty story told of her habits, by Aristotle, 

 the old Greek naturalist, which every one believed 

 until quite lately. He said that she rode on the 



Fig. 170. Animal of Argonauta Argo. 



extremities of the arms against her body, and it is 

 the inside of these arms that secrete the paper-like 

 shell, which is only a sort of cradle for her eggs. 

 Not so with the pearly nautilus, which is furnished 

 with a beautiful coiled-up pearly shell, formed on 

 the outside of the animal. This shell is divided 



Fig. 171. Shell of Argonauta Argo. 



into numerous chambers, and the animal living in 

 the outer one builds a partition across the back 

 part of it as the shell grows. 



Cuttle-fishes are sometimes used for food by the 

 Brazilians, and different species may be seen in the 

 markets, where one frequently finds them still 

 alive. Sometimes, as we stoop to examine one, its 



l 2 



