4/6 THE OCEAN WORLD. 



horny hoop, the outer and anterior margin of which is developed intc 

 a series of sharp curved teeth, which can be firmly pressed into the 

 flesh of a struggling prey by the contraction of the surrounding trans- 

 verse fibres, and can be withdrawn by the action of the retracting 

 fibres of the piston. " Let the reader," the Professor adds, " picture 

 to himself the projecting weapon of the horny hoop developed into a 

 long, curved, sharp-pointed claw, and these weapons clustered at the 

 expanded terminations of the tentacles, and arranged in a double 

 alternate series along the internal surface of the eight muscular feet, 

 and he will have some idea of the formidable nature of the carnivorous 

 cephalopod." The Professor notices another structure which adds 

 greatly to the prehensile powers of theuncinated Cephalopods. " At 

 the extremities of the long tentacles a cluster of small, simple, unarmed 

 suckers may be observed at the base of the expanded part. When 

 these latter suckers are applied to one another, the tentacles are 

 firmly locked together at that part, and the united strength of both 

 the elongated peduncles can be applied to drag towards the mouth 

 any resisting object which has been grappled by the terminal hooks. 

 There is no mechanical contrivance which surpasses this structure ; 

 art has remotely imitated it in the fabrication of the obstetrical 

 forceps, in which either blade can be used separately, or, by the 

 interlocking of a temporary blade, be made to act in combination." * 



If we study the general aspect of the animal more closely, we find 

 that the arms which serve at once as organs of locomotion for 

 swimming, for creeping, and as prehensile organs for seizing and 

 retaining its prey are conical, very long, and all of the same form. 

 Each of them has towards its axis a longitudinal canal, which encloses 

 a great nerve, and is also surrounded with muscular fibres, arranged 

 in rays. The suckers, already described, occupy all the internal 

 surface of the eight tentacular arms, which are arranged in two rows, 

 having the form very nearly of a semi-spherical capsule. Of these 

 suckers, each arm of the cuttle-fish carries about 240, the total 

 number being nearly 1,000. The mouth we have already described, 

 in Dr. Roget's words : " The teeth move vertically, much as the 

 cutting edge of the two blades of a pair of scissors move upon each 

 other, tearing the prey by the assistance of their hooked terminations." 



The tongue is covered on its upper part by a thick horny surface, 

 bristling in the centre with a series of recurved teeth, while its edge 

 is armed with three other erect teeth, which are slender and hooked. 

 The oesophagus is long and slender. At the abdomen the gullet 



* " Cyclopaedia of Anatomy." 



