PARTS OF ANIMALS, IV. ix. 



arrangement as one another, but it differs completely 

 from that of the others, as the tail-end of these 

 creatures is bent right over to meet the front, 

 just as if I were to bend the straight hne over 

 until the point D met the point A. Such 



A B C D 



then, is the disposition of their internal parts. 

 Round them, in Cephalopods, is situated the sac (in 

 the Octopuses and in them only it is called the head) : 

 in the Testacea the corresponding thing is the conical 

 shell. The only difference is that in the one case 

 the surrounding substance is soft, and in the other 

 Nature has surrounded the flesh with something 

 hard, to give them the preservation they need owing 

 to their bad locomotion. As a result of the above- 

 mentioned arrangement, in both sets the residue 

 leaves at a point near the mouth : in the Cephalopods 

 under the mouth, in the conical Testacea at the side 

 of it. 



So what we have said explains why the feet of 

 Cephalopods are w^here they are, quite differently 

 placed from all other animals' feet. Sepias and 

 Calamaries, however, being swimmers merely, differ 

 from the Octopuses, which are walkers as well ; they 

 have six small feet above the teeth, and of these the 

 ones at each end are larger ; the remaining two out 

 of the total eight are down below and largest of 

 all. These creatures have their strongest feet do^v^l 

 below, just as quadrupeds have their strongest limbs 

 at the back ; and the reason is that they carry the 

 weight of the body and they chiefly are responsible 

 for locomotion. The two outer feet are larger than 

 the inner ones because they have to help the others 



' 359 



