FORAMINIFEBA OF CHALK. 539 



is amply made up by the number of the individuals, which she 

 multiplies with admirable promptitude to infinity. The remains 

 of such minute animals have added much more to the mass of 

 materials which compose the exterior crust of the globe, than 

 the bones of Elephants, Hippopotami, and Whales." 



1112. But these facts sink into insignificance, when compared 

 with those lately revealed by the researches of Ehrenberg, in 

 regard to the existence of a race still more minute, and its multi- 

 plication to a still more inconceivable extent. In examining, 

 with a high magnifying power, Chalk or Whiting in a state of 

 extremely minute division, two sets of particles may be distinctly 

 seen; one set having a crystalline structure, and the other 

 presenting some indications of an organic aspect. If these be 

 rendered more transparent by the use of Canada balsam, it is 

 seen that they are polythalamous (many-chambered) shells of 

 great minuteness ; some of them in fragments, and others nearly 

 or quite perfect. The size of these varies from -fa to -^^ of 

 a line ; and when, as in the Chalk of Southern Europe, they 

 constitute nearly the whole mass, there must usually be above a 

 million in every cubic inch. In the fourth part of a cubic line, 

 or T ^ of a grain, from 150 to 200 can be ascertained to exist ; 

 and thus there would be from 1800 to 2400 in each grain, and 

 far above ten millions in every pound of chalk. In the chalk of 

 this country, and of other parts of the north of Europe, there is 

 a predominance of particles of a somewhat crystalline character ; 

 but even these have in all probability once been combined in 

 organic structures. In pursuing his researches on this subject, 

 it occurred to Ehrenberg to examine the finer particles of calca- 

 reous matter, which have been artificially separated from chalk, 

 and are employed for various purposes. Of such, the glazing of 

 the papers with which the walls of apartments are sometimes 

 covered, and that of visiting cards, are partly composed ; and on 

 scraping a little of this, and subjecting it to microscopic exami- 

 nation, he was delighted to find the organic structure almost 

 everywhere apparent. 



