208 THE ORGANIZATION 



which it is attached along the lower side, (ma,} from head to tail. 

 On the upper side of the neck there is a hollow, conical projection 

 (/) called the funnel, from the base of which a flap (f 1 ) passes 

 down each side of the body to the point (ma) where the latter is 

 joined to the sac (ma 1 ). By the help of these two parts, then, the 

 muscular sac, i. e., mantle, and the funnel, all the various motions 

 of the body are accomplished. When the edge (fig. 124, 1) of the 

 mantle is open at the neck, water flows in until the space (me) 

 around the body is filled. If, now, the animal wishes to swim, it 

 contracts the mantle, and the water consequently seeks an outlet ; 

 but as the flap (f 1 ) of the funnel acts as a valve by pressing 

 against the inner face of the mantle, the water is prevented from 

 going out by the way it came in, and therefore is projected with 

 great force through the funnel (f) toward the head, and the re- 

 action of the outgoing current propels the body in the contrary 

 direction, L e., backwards. In order to reverse the direction the 

 funnel is bent upon itself, as you would flex the finger, and then 

 the water being forced out toward the tail, the reaction moves 

 the body head foremost. If the creature wishes to turn round, 

 the funnel is simply bent to one side, and the reaction of the 

 excurrent water throws the head in the contrary direction. At 

 the posterior end of the body there is a fin-like organ, (fn,) which 

 is attached along its mid-line to the lower side of the tail. 

 When the Squid is swimming, this fin is usually folded around 

 the tail ; but whilst turning or moving gently, it is used as a 

 balancer, by spreading it out, and waving its edges up and down, 

 as fishes do with the fins on each side of the neck. 



The head (hd) is set off from the rest of the body by a slight 

 constriction, or neck. Around the mouth, (m,) which is at the 

 end of the head, there are arranged, right and left, ten arms, (t, t 1 ,) 

 five on one side and five on the other, set so closely together as 

 to form a complete circle above, at the sides, and below. Of 

 these ten, eight (t) are in one circle, and the other two (t 1 ), much 

 larger than the rest, are attached one on each side immediately 

 within the circle of eight, and in the interval between the first 

 and second upper arms of the right and left sides. The whole 



