FROM LAMARCK TO ST. HILAIRE 275 



He called his theory 'Bildung und UmbildungJ 

 or 'Formation and Transformation.' Morj^hol- 

 ogy was Goethe's favorite study, and upon trans- 

 formation depended all his ideas of the descent 

 theory. Phyletic series and the methods of ascer- 

 taining them were wholly unknown to him, but 

 structural series, or the modifications of a primi- 

 tive type or archetype, exhibited successively in 

 the lower and higher types of plants and in the 

 lower and higher types of animals, were clearly 

 perceived, and, as we have seen above, they led 

 Goethe to a thoroughly philosophical interpreta- 

 tion of structures in all stages of Evolution, in 

 the three phases of development, balance, and 

 degeneration. 



The 'Urbild,' or primitive type, was composed 

 of the internal original common characters — as 

 we would say, the *stem characters' — lying at the 

 base of all forms, and these original structures 

 were preserved by heredity. The preservation of 

 this hereditary type was opposed by a continu- 

 ous progressive development, somewhat in the 

 Aristotelian sense, and this was necessitated by 

 the adaptive reactions of the organism to the 

 outer world. The hereditary type is the centripe- 

 tal structural force, or specification, while pro- 

 gressive development is the centrifugal structural 

 force, or metamorphosis. Goethe prized highly 

 the conception of these two opposed forces, which 



