Toads enclosed in Stone and Wood. 29 



cession 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 purpose, on the north side of the trunk of an apple 

 tree ; two being placed 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 as to exclude access of insects, and 

 apparently 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 atmospheric air; and from the experiments in the larger 

 cells within the block of oolite limestone, it seems probable that 

 they cannot survive two years entirely excluded from food ; we 

 may therefore conclude, that there is a want of sufficiently mi- 

 nute and accurate observation 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 in- 

 creased in weight at the end of a year, notwithstanding the care 

 that was taken to enclose them perfectly by a luting of clay, 

 shews how very small an aperture will admit minute insects suffi- 

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

 slightly cracked, the communication though small was obvious; 

 but, in the cell No. 9, where the glass cover remained entire, and 

 where it appears certain, from the increased weight of the enclosed 

 animal, that insects must have found admission, we have an ex- 

 ample of these minute animals finding their way into a cell, to 

 which great care had been taken to prevent any possibility of 

 access. 



Admitting, then, that toads are occasionally found in cavities 

 of wood and stone, with which there is no communication suffi- 

 ciently large to allow the ingress and egress of the animal en- 

 closed in them, we may, I think, find a solution of such pheno- 

 mena in the habits of these reptiles, and of the insects which 

 form their food. The first effort of the young toad, as soon as 



