CEPHALOPODS. 319 



their extremities, which are enlarged and dilated to afford 

 them a firmer and broader seat. These tentacula, except 

 in one or two instances, " arise from the cephalic cartilage, 

 close together, internal to the origins of the ventral pair of 

 brachia ; they proceed at first outwards to a large mem- 

 branous cavity situated anterior to the eyes, and thence 

 emerge between the third and fourth arms on either side." 

 Their cups or suckers are also encircled with a horny 

 spinous ring ; and these spines are sometimes so much de- 

 veloped as to deserve the appellation of claws, — a struc- 

 ture which, you at once perceive, must greatly increase 

 their powers of retention. With these formidable tentacula, 

 extended in front to the full, the prey is caught, and firmly 

 grasped ; and now by their being shortened and coiled up 

 in the infraorbital cavities whence they emerged, it is 

 brought within the reach of the shorter arms, whose func- 

 tion is to retain it against the mouth until it is devoured. 



I cannot enter into any detail of the variations which 

 these organs — the arms and tentacula — undergo in the dif- 

 ferent genera, but among them there are two so very sur- 

 prising as necessarily to challenge some notice. In the Ony- 

 choteuthis — the most formidable of Cephalopods — there are 

 at the extremities of the long tentacula, besides the unci- 

 nated acetabula or cups, a cluster of small, simple, unarmed 

 suckers 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 inter- 

 locking of a temporary joint, be made to act in combina- 

 tion."* — The final cause of my other example is not so 

 obvious, for the economy of the animal appears to be un- 

 known. Take up your pencil and draw for me a decapod 

 cuttle-fish. Let the form be like that of a Loligo, the body 

 of small size, but give whatever length to the tentacula you 

 may deem fair and reasonable for a body of more than twice 

 its bulk. There is an unlicence certainly in the drawing, 

 but nature has surpassed your fanciful portrait. The Loli- 

 gopsis veranii does not exceed four inches in length, — the 



* Owen in Cyclop. Anat. and Phys. i. 529. To this article of Mr. 

 Owen's, I would wish to refer the student for the fullest and most accurate 

 history of the Cephalopoda. 



