274 The Vitality of Toads enclosed in Stone and Wood. 



We can therefore scarcely argue with certainty from the death of all 

 these individuals within two years, as to the duration of life, which 

 might have been maintained had they retired spontaneously and fallen 

 into the torpor of their natural hybernizalion in good bodily condition. 



The results of our experiments amount to this ; all the toads both 

 large and small inclosed in sandstone, and the small toads in the lime- 

 stone also, were dead at the end of thirteen months. Before the ex- 

 piration of the second year, all the large ones also were dead; these 

 were examined several times during the second year through the 

 glass covers of the cells, but without removing them to admit air ; 

 they appeared always awake with their eyes open, and never in a 

 state of torpor, their meagreness increasing at each interval in which 

 they were examined, until at lengdi they were found dead ; those two, 

 also, which had gained an accession of weight at the end of the first 

 year, and were then carefully closed up again, were emaciated and 

 dead before the expiration of the second year. 



At the same time that these toads were enclosed in stone, four other 

 toads of middling size were enclosed in three holes cut for this pur- 

 pose, on the north side of the trunk of an apple tree ; two being pla- 

 ced in the largest cell, and each of the others in a single cell ; the 

 cells were nearly circular, about five inches deep and three inches in 

 diameter ; they were carefully closed up with a plug of wood, so aa 

 to exclude access of insects, and apparendy were air-tight; when 

 examined at the end of a year, every one of the toads was dead" 

 and their bodies were decayed. 



From the fatal result of the experiments made in the small cells 

 cut in the apple tree, and the block of compact sandstone, it seems 

 to follow that toads cannot live a year excluded totally from atmos- 

 pheric air ; and, from the experiments in the larger cells within the 

 block of oolite limestone, it seems probable that they cannot sur- 

 vive two years entirely excluded from food ; we may therefore con- 

 clude, that there is a want of sufiiciently minute and accurate obser- 

 vadon in those so frequently recorded cases, where toads are said to 

 be found alive within blocks of stone and wood, in cavities that had no 

 communication whatever with the external air. The fact of my two 

 toads having increased in weight at the end of a year, notwithstand- 

 ing the care that was taken to enclose them perfectly by a luting of 

 clay, shews how very small an aperture will admit minute insects 

 sufficient to maintain life. In the cell No. 5, where the glass was 

 slightly cracked, the communication though small was obvious ; but 



