226 f^g Sfermons, $ssap, mtir |]tomfas. [x. 



evidence of any such modification, or demonstrates it to 

 have been very slight; and as to the nature of that 

 modification, it yields no evidence whatsoever that the 

 earlier members of any long-continued group were more 

 generalized in structure than the later ones. To a certain 

 extent, indeed, it may be said that imperfect ossification 

 of the vertebral column is an embryonic character; 

 but, on the other hand, it would be extremely incor- 

 rect to suppose that the vertebral columns of the older 

 Vertebrata are in any sense embryonic in their whole 

 structure. 



Obviously, if the earliest fossiliferous rocks now known 

 are coeval with the commencement of life, and if their 

 contents give us any just conception of the nature and 

 the extent of the earliest fauna and flora, the insig- 

 nificant amount of modification which can be demon- 

 strated to have taken place in any one group of animals, 

 or plants, is quite incompatible 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 hypfchesis of progressive 

 modification must be compatible with persistence with- 

 out progression, through indefinite 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 

 Palaeozoic, Mesozoic, and Cainozoic faunae and florae, 

 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 palaeontology as they appear, 

 and have for some years appeared, to the mind of an 

 inquirer who regards that study simply as one of the 



