4>I0 Natural Hktory of Molluscous Anhndls : — 



gasteropodes in question.* Having secured the shell, by 

 applying to it the disk of the foot, they apply, to the point 

 where they mean to penetrate, the apex of their proboscis, 

 and now by a constant rubbing or grating of their filiform 

 rough spinous tongue, assisted, perhaps, by some corrosive 

 quality of the saliva, they succeed ultimately in perforating 

 the shell. Surely the " patientia vincit " [patience over- 

 comes] had never a more remarkable illustration ; for the 

 ^iiccina may work for days, and even weeks, before the life 

 of the animal attacked is fully extinguished. 



But the proboscis (Jig. 50.), the organ by which this work 

 is effected, demands a more detailed description ; for its me- 

 chanism is scarcely less wonderful than 

 the analogous organ of the elephant. It 

 is cylindrical and of considerable length, 

 and when not in use is kept retracted 

 within the body, where it lies beyond the 

 reach of injury. The better to under- 

 stand its structure, we may represent it 

 as being formed of two flexible cylinders, 

 one within the other, and which are united 

 at the upper margin, so that, in drawing out the interior cy- 

 linder, we can only lengthen it at the expense of the other ; 

 and, on pushing it back again, we, in shortening it, give cor- 

 responding extension to the exterior, but the latter lengthens 

 only on the upper side, because it is fixed to the parietes of 

 the head by its inferior margin. Let us now add a number of 

 longitudinal muscles, all of them very much divided at both 

 extremities : the stripes of their internal or superior extremity 

 are attached to the parietes of the body, those of the opposite 

 end all along to the internal surface of the inner cylinder of 

 the proboscis ; and their action, consequently, is to draw this 

 cylinder and the whole proboscis inwards. When thus re- 

 tracted, a great part of the internal surface of the interior 

 cylinder makes part of the external surface of the exterior 

 cylinder, and it is just the contrary when the proboscis is 

 elongated and protruded. The protrusion of the inner cylinder 

 by the unrolling of the exterior, or, which is the same thing, 

 the evolution of the proboscis, is effected by its own peculiar 

 annular muscles : these encircle it all its length, and, by con- 



* " The purple hath a tongue of a finger long, pointed in the end so 

 sharpe, and hard withall, that it is able to bore an hole and pierce into 

 other shell-fishes, and thereby shee feeds and gets her living." (Holland's 

 Plin.y i. 258.) The ancients were better informed on this subject than 

 some modern writers, who have attributed these operations to the Trochus. 

 (See Smellie's Phil, of Nat. Hist., i. 396.) 



