THE ANIMAL KINGDOM. 31 



a considerable number of fresh-water Infusoria or micro- 

 scopic shells. It is clear, therefore, that these alimentary 

 rocks owe their nutritive properties to animal matter which 



14. Microscopic view of Infusoria in mountain-meal of Ebsdorf. 1 



they have retained, and that it is this which renders them 

 of any value as food. 



But the revolutions of the earth have not stopped here ; 



1 In Europe the most celebrated deposits of mountain-meal are those of Lap- 

 land, of Degerna and Lollhagysyb'n in Sweden, of Ebsdorf in the Luneburg 

 Heath, and of Santafiora in Tuscany. Smaller deposits are found in Greece, 

 Hungary, Bohemia, France, and elsewhere. I myself discovered one in 1846 at 

 Louie, in South Portugal. Many of these accumulations of mountain-meal are of 

 great importance to man, being mixed with common meal and used as food, though 

 the substance possesses no conceivable alimentary properties. In Europe it is 

 only the mountain-meal of Lapland and Sweden that is so used. Of the moun- 

 tain-meal of Lollhagysyon, for example, there are every year many hundred wag- 



