74 SELECTED ESSAYS FROM LAY SERMONS 



their organic nature. Dr. Wallich verified my observation, 

 and added the interesting discovery that, not unfrequently, 

 bodies similar to these '^coccoliths" were aggregated to- 

 gether into spheroids, which he termed ^' coccospheres.''^ 

 So far as we knew, these bodies, the nature of which is 

 extremely puzzling and problematical, were peculiar to 

 the Atlantic soundings. But, a few years ago, Mr. Sorby, 

 in making a careful examination of the chalk by means of 

 thin sections and otherwise, observed, as Ehrenberg had 

 done before him, that much of its granular basis possesses 

 a definite form. Comparing these formed particles with 

 those in the Atlantic soundings, he found the two to be 

 identical; and thus proved that the chalk, like the sur- 

 roundings, contains these mysterious coccoliths and cocco- 

 spheres. Here was a further and most interesting confir- 

 mation, from internal evidence, of the essential identity of 

 the chalk with modern deep-sea mud. GlobigerincB, cocco- 

 liths, and coccospheres are found as the chief constituents 

 of both, and testify to the general similarity of the condi- 

 tions under which both have been formed.^ 



The evidence furnished by the hewing, facing, and 

 superposition of the stones of the Pyramids, that these 

 structures were built by men, has no greater weight than 

 the evidence that the chalk was built by Globigerince and 

 the belief that those ancient pyramid-builders were terres- 

 trial and air-breathing creatures like ourselves, is not 

 better based than the conviction that the chalk-makers 

 lived in the sea. But as our belief in the building of the 



1 1 have recently traced out the development of the "coccoliths" 

 from a diameter of y^Vo^^ °^ ^^ ^^^^ ^P ^° their largest size (which is 

 about jg'oo'-^)' ^^^ "^ longer doubt that they are produced by inde- 

 pendent organisms, which, like the Globigerince, live and die at the 

 bottom of the sea. 



