28 THE HISTORY OF CREATION. 



organisms, as for- example the Medusse, the naked molluscs 

 without shells, a large portion of the articulated animals, 

 almost all worms, and even the lowest vertebrate animals, 

 possess no firm and hard parts capable of being petrified. In 

 like manner the most important parts of plants, such as the 

 flowers, are for the most part so soft and tender that they 

 cannot be preserved in a recognizable form. We therefore 

 cannot expect to find any petrified remains of these import- 

 ant organisms. Moreover, all organisms at an early stage of 

 life are so soft and tender that the}" are quite incapable of 

 being petrified. Consequently all the petrifactions found in 

 the neptunic stratifications of the earth's crust comprise 

 altogether but a very few forms, and of these for the most 

 part only isolated fragments. 



We must next bear in mind that the dead bodies of the 

 inhabitants of the sea are much more likely to be preserved 

 and petrified in the deposits of mud than those of the in- 

 habitants of fresh water and of the land. Organisms living 

 on land can, as a rule, become petrified only when their 

 corpses fall accidentally into the water and are buried at the 

 bottom in the hardening layers of mud. But this event 

 depends upon very many conditions. We cannot therefore 

 be astonished that by far the majority of petrifactions belong 

 to organisms which have lived in the sea, and that of the 

 inhabitants of the land proportionately only very few are 

 preserved in a fossil state. How many contingencies come 

 into play here we may infer from the single fact that of 

 many fossil mammals, in fact of all the mammals of the 

 secondary, or mesozoic epoch, nothing is known except 

 the lower jawbone. This bone is in the first place com- 

 paratively solid, and in the second place very easily separates 



