THE ANIMAL KINGDOM. 27 



lowing words to the Academy of Sciences : " I have seen 

 all these marvels. I have compared them with the beauti- 

 ful drawings of living species made by M. Ehrenberg, and 

 I can no longer retain the slightest doubt." 



Thus it is demonstrated that rocks which belong to the 

 most ancient epochs of life on our globe, and which some- 

 times contain strata of vast magnitude, are only so many 

 graveyards of the Infusoria. The mind grows bewildered 

 in trying to find out in what mysterious way these many 

 invisible animalcules could be accumulated to form such 

 extraordinary heaps of corpses. 



The city of Richmond, Virginia, is the centre of one of 

 these districts, where, according to the beautiful saying 

 of Shelley, every grain of dust was once endued with life. 

 The deposit of microscopic skeletons attains a depth of sev- 

 eral hundred yards. If as many human mummies were 

 laid one upon another they would form a mountain, the 

 height of which would almost equal a semi-diameter of the 

 earth ! (W. de Fonvielle.) 



It is very easy to verify these statements. The reader 

 has only to scrape with a knife the surface of a morsel of 

 one of these tripolis, to let the dust fall on a plate of glass, 

 and to examine it with the microscope after having mixed 

 it with a little water. He will be astonished to see noth- 

 ing but carapaces of animalcules. 



The confirmation of what we have said is chiefly met 

 with in the tripoli of Bilin in Bohemia, and in those of the 

 Isle of France. 



The learned Schleiden calculated that a cubic inch of the 

 former contains, in round numbers, 41,000,000 of animal- 



