THE ANIMAL KINGDOM. 33 



that these latter have determined the occurrence of geo- 

 logical phenomena of immense extent and importance. 



This is the case with the Miliolce, little shells which owe 

 their name to the fact 

 that their size does not 

 exceed that of a grain 

 of millet, and indeed is 

 often less. They were 

 so numerous in the an- 

 cient seas of the Paris 

 basin that in settling 

 down they formed 



15. Magnified Miliola, with its Capillary Appendages 



mountains, which are projected. 



now quarried to build our towns : the greatest part of the 

 stone in the houses of Paris is composed simply of the cara- 

 paces of these molluscs agglomerated and closely cemented 

 together ; so that one may say without hyperbole that 

 our splendid capital is built of microscopic shells. 



An observation by M. Defrance will give an idea of the 

 minuteness of the Stone Miliola, the species which prin- 

 cipally constitutes the coarse limestone used in building. 

 He has computed that a box with a capacity of a cubic line 

 would contain as many as ninety-six ! 



What a mystery envelops the life of these fragile shells, 

 which, in spite of their insignificant size, have played such 

 a great part in the geologic phenomena of the tertiary 

 epoch ! Nature here reveals her infinite power by regain- 

 ing, through prodigious fecundity, what she loses in bulk. 

 Hence, as Lamarck has said, the vestiges of some micro- 

 scopic creatures have had more influence upon the crust of 



3 



