Bibliographical Notices. 55 



sale scale on the Continent, and every philosopher was anxious to cut 

 off a head. Even the great Voltaire followed the universal fashion ; 

 and his experiences were published in the 'Questions sur 1' Encyclo- 

 pedic' In these he mentions having operated on twenty brown 

 slugs and a dozen snails ; and he afterwards records with great pride 

 and satisfaction ' mes Limaces' and 'mes Escargots ' showing their 

 budding heads and horns, and doing as well as might be expected 

 under the circumstances." Accident some years ago enabled us to 

 verify the observations of Voltaire, Midler, and others upon this sub- 

 ject. Unaware at that time of the wonderful tenacity of life in the 

 Helices, and being desirous of examining the jaws of H. aspersa, we 

 suddenly decapitated a snail, while crawling, with a single stroke of 

 a penknife. We believed, in doing this, that we had adopted a plan 

 of killing the snail which would result in instantaneous death, while 

 the mode of death was also best suited to our immediate purpose. 

 The shell containing the carcase was thrown from the open window 

 into the garden, while the head was dissected, and the jaws extracted 

 and mounted. Nothing more was thought of the matter until, about 

 six weeks subsequently, we lighted, while gardening, upon the iden- 

 tical snail-shell, which was easily recognizable in consequence of a 

 repair, and to our astonishment noticed a thin filmy epiphragm closing 

 the mouth of the shell. The mollusk was still alive ; and on tempt- 

 ing it out by immersion in tepid water, the headless trunk was pro- 

 truded from the shell. The .poor animal's neck was healed over, and 

 we found that we had been unintentionally guilty of a barbarous act 

 of mutilation. We were, however, of course extremely interested in 

 the result, and the snail was carefully kept for future observation. 

 It lived for a year and two or three months. During this time it 

 was occasionally clipped in milk, with the hope that nourishment 

 might thus be imbibed through the pores of the skin. Under this 

 stimulus, the snail would protrude its poor guillotined remains from 

 the shell ; there were, however, but faint signs of reproduction. 

 The last time it was seen alive, the head was represented by a knob- 

 formed projection, on which two minute tubercular eminences repre- 

 sented the upper antennae. 



The author gives a brief analysis of the various solutions which 

 have been offered of the much-vexed question of the means by which 

 the burrowing Mollusca penetrate stone, wood, cork, and other sub- 

 stances, and then proceeds to propound a new theory — new, that is, 

 to modern times, — which we give to our readers without comment. 



" I profess myself to be a follower of Sellius," a Dutch philo- 

 sopher who wrote a learned treatise on the Ship-worm about a hun- 

 dred and thirty years ago ; " and I am convinced that the sole in- 

 strument of perforation, by the Mollusca, of stone, wood, and other 

 substances is in every case their foot, or muscular disk, which is 

 closely applied to the concave end of the hole, and is constantly 

 supplied with moisture through the glandular tissues of the body. 

 The strength of this organ may be easily tested by any one who tries 

 to remove a limpet from its native rock, after having touched it, and 

 thus given it notice of his intention. By this simple yet gradual 



