194 FROM LAMARCK TO ST. HILAIRE. 



could only have arisen by the development from generation to gen- 

 eration of similar forms ; these primitive forms are the Encrinites, 

 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 decline ; the 

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

 catastrophes of Nature which have caused extinction, 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 Evolution, al- 

 though a strong advocate of it. His ideas upon 

 descent are much less clear and accurate than those 

 of Lamarck ; and in his views of the original, spon- 

 taneous origin of some of the higher forms of life, 

 as shown in the sentence last quoted, he is very far 

 afield. Haeckel is mistaken when he states that 

 Treviranus refers to the lowest organisms in the 

 term ' zoophytes,' for Treviranus couples with this 

 term such complex forms as Crinoids and Ammo- 

 nites. As to the factors of Evolution, he does not 

 advance beyond Buffon, and in his general concep- 

 tion he virtually takes the position held much 

 earlier by Goethe, for he summarizes his views 

 in the sentence : " In every living being there exists 

 the capability of an endless variety of form- 

 assumption ; each possesses the power to adapt its 

 organization to the changes of the outer world, and it 



