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. 

 ^ Bpnes^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 



