FOSSILS, AND HOW THEY ARE FORMED 



"How of a thousand snakes each one 

 Was changed into a coil of stone." 



Fossils are the remains, or even the indica- 

 tions, of animals and plants that have, through 

 natural agencies, been buried in the earth and 

 preserved for long periods of time. This may- 

 seem a rather meagre definition, but it is a dif- 

 ficult matter to frame one that will be at once 

 brief, exact, and comprehensive ; fossils are not 

 necessarily the remains of extinct animals or 

 plants, neither are they, of necessity, objects 

 that have become petrified or turned into stone. 

 Bones of the Great Auk and Rytina, which 

 are quite extinct, would hardly be considered 

 as fossils ; while the bones of many species of 

 animals, still living, would properly come in 

 that category, having long ago been buried by 

 natural causes and often been changed into 



