. vu OF FOSv 77 



carcases of mammoths and rhinoceroses which have been 

 preserved for ages with their flesh and hair, frozen up in 

 some of them the skeleton of a 



stag preserved in a peat-bog; the scales and tc 

 fishes scattered through a solid limestone ; the shells of 

 mnlluscra, thr calcareous framework of corals, the com 

 pressed leaves, fruits, and stems of plants ; in short, any 

 and every part of an organism which has been imbedded 

 in a geologic.) r what may ! 



<1 whether or not it has been 

 partially or wholly |>ctrified. 

 Hut nut merely HUM 



organism ; we may properly class also with fossils even- 

 substance or marking which has been connected in any 

 way with the organism and bears witness as to its exist- 

 ence and character. Thus, the resin of a tree, the trail 

 or the castings of a worm, the droppings of animals, 

 he tools and weapons of man, may all become fossils 

 and yield their evidence as to former conditions of life. 



As the circumstances under which fossils have been 

 entombed have greatly varied, the observer must be pre- 

 pared for the most extraordinary differences in the appear- 

 ance of even the same species of fossil in different places 

 and kinds of rock. In some rare examples the body of 

 an animal has been so entirely and perfectly preserved 

 that, as is said to have been the case with the Siberian 

 mammoth just referred to, its flesh may be torn in pieces 

 and devoured by beasts and birds of prey. As a rule, 

 however, the soft parts of the organism are gone. Where 

 there have been harder parts, such as an internal skeleton 

 external covering, these may still remain nearly or 



