268 TORPIDITY. 



put into water, though an mterval of more than four months 

 had elapsed. Deshajes explains this long endurance in 

 this genus from a peculiarity in the structure of the respi- 

 ratory organs, for not only is the branchial cavity more than 

 ordinarily capacious, but there is a supplementary sac which 

 is not found in other genera of its order. After the snail 

 has withdrawn itself, and closed the aperture of its shell 

 with the operculum, the water is retained in this sac, and 

 the branchias thereby kept in a moist and unshrivelled con- 

 dition ; * while, perhaps, its contact with a living surface 

 prevents the retained fluid running into putrefaction. Mr. 

 Lyell tells us that " four individuals of a large species of 

 Bulimus, from Valparaiso, were brought to England by 

 Lieutenant Graves, who accompanied Captain King in his 

 late expedition to the Straits of Magellan. They had been 

 packed up in a box and enveloped in cotton, two for a space 

 of thirteen, one for seventeen, and a fourth for upwards 

 of twenty months ; but on being exposed by Mr. Broderip 

 to the warmth of a fire in London, and provided with tepid 

 water and leaves they revived, and are now living in Mr. 

 Loddiges's palm-house." -f Dr. Elliotson put a garden-snail 

 " into a dry closet, without food, a year and a half ago ; 

 it became torpid, and has remained so ever since, except 

 whenever I have chosen to moisten it. A few drops of 

 water revive it at any time."]; Similar instances may be 

 found in some of the periodical journals ; but they are as 

 nothing when compared with the snails of Mr. Stuckey 

 Simon, a merchant of Dublin, which, on being immersed 

 in water, recovered and crept about after an uninterrupted 

 torpidity of at least Jlfteen years; § and I agree with Mr. 



* Ann. dcs Sc. Nat. xxix. 270. 



t Princip. Gcol. ii. 109. 8vo. edit. See also Edinb. New Phil. Jouin. 

 xvi. 392, for some similar facts. 



J Blumenbach's Pliysiology, p. 182. — In the Ephemerid. Acad. Leo- 

 pold, cent. 7. p. 184, a case of a boy is related who voided four shelled 

 snails that he had swallowed ; and the snails, on their expulsion, crept 

 about with sufficient vivacity. 



§ "Mr. Stuckey Simon, a merchant of Dublin, whose father, a fellow of 

 the Royal Society, and a lover of natural history, left to him a small col- 

 lection of fossils and other curiosities, had among tliem the shells of some 

 snails. About fifteen years after his father's death (in whose possession 

 they continued many years), he by chance gave to his son, a child 

 about ten years old, some of these snail-shells to play with. The boy put 

 them into a fiower-pot, which he filled with water, and the next day into a 

 basin. Having occasion to use this, Mr. Simon observed that the animals 

 had come out of their shells. He examined the child, who assured him 

 that they were the same he had given him, and said he had also a few more, 

 which he brought. Mr. Simon put one of these into water, and in an hour 

 and a half after observed, that it had put out its horns and body, which it 



