PREVIOUS TO THE LAST GEOLOGICAL REVOLUTION. 7 



appearance of crystallized sugar to the substances covered by 

 them. 



Whoever visits these caverns to admire the beauty of their 

 fantastic draperies, will dwell with most pleasure on the for- 

 mations of this class : while for the zoologist they possess 

 less interest, since the substances they enclose are most com- 

 monly of very recent origin. Under the stalagmitic mass, and 

 forming, as it were, the nucleus of these " confetti," I have 

 often found recent bones of existing animals, shells, nay, even 

 a piece of charcoal, probably left by savages. Not unfre- 

 quently do we detect nature in the very act of forming these 

 incrustations, where, in a heap of bones lying on the floor, 

 some are already entirely enveloped in stalagmite, others stick 

 half out of it, while others again lie perfectly untouched, and 

 awaiting the incrustation that will veil them from our view, 

 and preserve them perhaps for the investigations of a future 

 generation. Forasmuch as this formation depends on agen- 

 cies which are in daily operation on the surface of the earth, 

 that it to say, on the infiltration of rain water through the fis- 

 sures and pores of limestone, there can be no reason for sup- 

 posing that it should not also have been going on at a period 

 before the introduction of the soil into the caves : and expe- 

 rience has convinced me that this is really the case. I have 

 frequently had occasion to observe, under the stratum of soil, 

 a similar stalagmitic incrustation, with those beautiful basin- 

 shaped crystallizations known hereby the name of "Pias," or 

 baptismal fonts. 



Besides these originating causes, there is scarcely a cave in 

 which we may not see, at least in time of rain, the water drop 

 from the roof, and form basins of a larger or smaller size. — 

 At the bottom and round the edge of these basins, the same 

 phenomena already described occur, and occasion incrusta- 

 tions and depressions in the floor. These two modes of for- 

 mation of the stalagmitic flooring of many caves are indubi- 

 table ; and where passages are narrow, and the quantity of 

 stalactite on the roof and walls considerable, they are sufli- 

 cient to account for the phenomenon : but at the same time 

 they are evidently insufficient, in many respects, to serve as 

 an universal explanation, as for instance, in the case of those 

 wide and spacious halls into which the caverns often expand, 

 where a coating of stalagmite covers the stratum of soil, like 

 ice on the smface of the lake, and yet where no dripping from 

 the roof betrays the actual presence of incrusting water, — no 

 stalagmitic crust on the walls or roof attests its agency in 

 time past. 



In the communication already cited, I have drawn atten- 



