48 GOETHE 



comes out in his treatment of the relation between structure 

 and function. Sometimes he takes the view that structure 

 determines function. "The parts of the animal," he writes, 

 " their reciprocal forms, their relations, their particular 

 properties determine the life and habits of the creature." T 

 \Ve are not to explain, he says, the tusks of the Babirnssa \ 

 by their possible use, but we must ask how it comes to have 

 tusks. In the same way we must not suppose that a bull 

 has horns in order to gore, but we must investigate the 

 process by which it comes to have horns to gore with. This 

 is the rigorous morphological view. On the other hand 

 he admits elsewhere that function may influence form. 

 Apparently he did not work out his ideas on this point to 

 logical clearness, and Radl 2 is probably correct in saying 

 that the following quotation with its double assertion 

 represents most nearly Goethe's position : 



"Also bestimmt die Gestalt die Lebenswcise des Thieres, 

 Und die Wcise zu leben, sie wirkt auf alle Gestalten 

 Machtig zuriick.' ):i 



His best piece of purely morphological work was his 

 theory of the metamorphosis of plants. Stripped of its vaguer 

 elements, and of the crude attempt to explain differences 

 in the character of plant organs by differences in the degree 

 of "refinement" of the sap supplied to them, the theory 

 is that stem-leaves, sepals, petals, and stamens are all 

 identical members or appendages. These appendages differ 

 from one another only in shape and in degree of expansion, 

 stem -leaves being expanded, sepals contracted, petals 

 expanded, and so on alternately. It is equally correct to 

 call a stamen a contracted petal, and a petal an expanded 

 stamen, for no one of the organs is the type of the others, 

 but all equally are varieties of a single abstract plant- 

 appendage. 



What Goethe considered he had proved for the append- 

 ages of plants he extended to all living things. Every living 

 thing is a complex of living independent beings, which " dcr 



1 Jtn/;curf, Cotta cd.,*ix., p. 465. 



- Geschichte der biologischen Tltcoricn, i., p. 266. 



Si i tin- form determines the manner of life of the animal, and the 

 manner of life in its turn reacts powerfully upon all forn 



