290 FROM THE GREEKS TO DARWIN 



which developed from them remained similar as long 

 as the environment was unaltered. But in studying 

 the form of any particular country, it is very hard 

 to determine which forms are native or autochtho- 

 nous, and which have spread into the country by mi- 

 gration from other countries. 



He then proceeds^ to propose anachronistic 

 theories of the abiogenetic origin of these Au- 

 tochthones : 



But how did these species arise? Were they born 

 fully formed, like Aphrodite, from sea-foam? Or as 

 simple zoophytes? They could only have arisen by 

 the development from generation to generation of 

 similar forms; these primitive forms are the Encri- 

 nites, Pentacrinites, Ammonites, and other zoophytes 

 of the Old World, from which all organisms of the 

 higher classes have arisen. Each species has its period 

 of growth, of full bloom, and dechne; the latter is 

 a period of degeneration. Thus, it is not only the 

 great catastrophes of Nature which have caused ex- 

 tinction, but the completion of cycles of existence, 

 out of which new cycles have begun. Thus, in Nature, 

 all is in a state of flux and transfer ; even man has 

 not reached the highest term of his existence, but will 

 progress to still higher regions, and produce a nobler 

 type of being. 



These sentences show that Treviranus did not 

 add anything to the main theory of transmuta- 



^Loc. city pp. 225-6. 



