396 THE BIOCOSMOS PARTICULARIZED. 



ginning of life on our planet till the present. 

 Stratification of the inorganic material has 

 preserved the contemporaneous organic re- 

 mains in various degrees of completeness, 

 from a mere trace or footprint, or bone, up 

 to the entire skeleton, whose flesh and hair 

 have continued undecayed in some instances 

 through being encased in ice. 



The science which deals with fossils is called 

 Paleontology, and has reached large propor- 

 tions. Fossils in the different successive 

 strata of the same region indicate which rocks 

 are older and which younger since the order 

 of ascent in the organic world is known, and 

 thus becomes the key for unlocking the rela- 

 tive age of the inorganic formations. Still 

 further, the same kinds of fossils appear in 

 strata very far apart, on a different conti- 

 nent perhaps; all such rocks are supposed to 

 have been formed in the same geologic period, 

 however distant they lie asunder. A geol- 

 ogist has recently estimated that the total 

 stratified order of the Earth's crust has a 

 thickness of fifty miles; but the strata are 

 much broken and interrupted through various 

 causes, and have to be put together from 

 diverse localities. Fossils have been called the 

 medals of creation, as they bear the .stamp 

 of the historic order of the Earth's evolution. 

 Still not the whole of this evolution can they 



