304 GEOLOGICAL CONTEMPORANEITY ix 



compatible with the hypothesis that all living 

 forms are the results of a necessary process of 

 progressive development, entirely comprised within 

 the time represented by the fossiliferous rocks. 



Contrariwise, any admissible hypothesis of pro- 

 gressive modification must be compatible with 

 persistence without progression, through indefi- 

 nite periods. And should such an hypothesis 

 eventually be proved to be true, in the only 

 way in which it can be demonstrated, viz. 

 by observation and experiment upon the 

 existing forms of life, the conclusion will 

 inevitably present itself, that the Pabeozoic 

 Mesozoic, and Cainozoic faunas and floras, taken 

 together, bear somewhat the same proportion to 

 the whole series of living beings which have 

 occupied this globe, as the existing fauna and 

 flora do to them. 



Such are the results of paleontology as they 

 appear, and have for some years appeared, to the 

 mind of an inquirer who regards that study simply 

 as one of the applications of the great biological 

 sciences, and who desires to see it placed upon the 

 same sound basis as other branches of physical 

 inquiry. If the arguments which have been 

 brought forward are valid, probably no one, in view 

 of the present state of opinion, will be inclined to 

 think the time wasted which has been spent upon 

 their elaboration. 



