276 The Vitality of Toads enclosed in Stone and Wood. 



It remains only to consider the case, (of which I know not any- 

 authenticated example), of toads that have been said to be found in 

 cavities within blocks of limestone to which, on careful examination, 

 no access whatever could be discovered, and where the animal was ab- 

 solutely and entirely closed up with stone. Should any such case ever 

 have existed, it is probable that the communication between this cavity 

 and the external surface had been closed up by stalactitic incrustation 

 after the animal had become too large to make its escape. A simi- 

 lar explanation may be offered of the much more probable case of a 

 live toad being entirely surrounded with solid wood. In each case 

 the animal would have continued to increase in bulk so long as the 

 smallest aperture remained by which air and insects could find ad- 

 mission ; it would probably become torpid as soon as this aperture 

 was entirely closed by the accumulation of stalactite or the growth of 

 wood ; but it still remains to be ascertained how long this state of 

 torpor may continue under total exclusion from food, and from exter- 

 nal air : and although the experiments above recorded shew that life 

 did not extend two years in the case of any one of the individuals which 

 formed the subjects of them, yet, for reasons which have been spe- 

 cified, they are not decisive to shew that a state of torpor, or suspend- 

 ed animation, may not be endured for a much longer time by toads 

 that are healthy and well fed up to the moment when they are finally 

 cut off from food, and from all direct access to atmospheric air. 



The common experiment of burying a toad in a flower-pot cover- 

 ed with a tile, is of no value, unless the cover be carefully luted to 

 the pot, and the hole at the bottom of the pot also closed, so as to 

 exclude all possible access of air, earthworms and insects. I have 

 heard of two or three experiments of this kind, in which these pre- 

 cautions have not been taken, and in which, at the end of a year, the 

 toads have been found alive and well. 



Besides the toads enclosed in stone and wood, four others were 

 placed each in a small basin of plaster of Paris, four inches deep 

 and five inches in diameter, having a cover of the same material care- 

 fully luted round with clay ; these were buried at the same time and 

 in the same place with the blocks of stone, and on being examined 

 at the same time with them in December, 1826, two of the toads 

 were dead, the other two alive, but much emaciated. We can only 

 collect from this experiment, that a thin plate of plaster of Paris is 

 permeable to air in a sufficient degree to maintain the life of a toad 

 for thirteen months. 



