their Respiration, 113 



But there are on record some extraordinary facts, which 

 seem to prove that, under certain conditions, all of which are 

 not yet known, the respiration of many Mollusca, more espe- 

 cially the terrestrial, may be suspended for an indefinite period, 

 and again renewed by the application of heat and moisture ; 

 life, as it were, keeping watch, and holding at bay every 

 destructive agent, but without giving any outward sign of her 

 presence and constant wakefulness, until the return of those 

 influences in which she joys. " All the land Testacea," to 

 use the words of Dr. Fleming, " appear to have the power 

 of becoming torpid at pleasure, and independent of any alter- 

 ations of temperature. Thus, even in midsummer, if we 

 place in a box specimens of the Helix hortensis, nemoralis, 

 or arbustorum, without food, in a day or two they form for 

 themselves a thin operculum, attach themselves to the side of 

 the box, and remain in this dormant state. They may be 

 kept in this condition for several years. No ordinary change 

 of temperature produces any effect upon them, but they 

 speedily revive if plunged in water. Even in their natural 

 haunts, they are often found in this state during the summer 

 season, when there is a continued drought. With the first 

 shower, however, they recover, and move about ; and at this 

 time the conchologist ought to be on the alert." {Phil, Zool.^ 

 vol. ii. p. 77.) I may illustrate these remarks, which are per- 

 fectly correct, by some additional examples; one or two of 

 which you may find to require an exercise of faith for which 

 you may not be altogether prepared. Mr. Lyell tells us that 

 " four individuals of a large species of B^limus, from Val- 

 paraiso, 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 en- 

 veloped in cotton, two for a space of thirteen, one for seven- 

 teen, 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 re- 

 vived, and are now living in Mr. Loddiges's palm-house.'* 

 {Princ. GeoL, vol. ii. p. 109.) 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 when- 

 ever I have chosen to moisten it. A few drops of water revive 

 it at any time." (Blumenbach's Phi/siologz/, p. 182.) 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 uninter- 



VoL. VII. — No. 38. I .^,^,.v, u.. 



