x8l THE HISTORY OF BIOLOGY 



fertilization's being called "eine geistige /4«^j-/-o;;z(?j-e." Even florescence is caused 

 by "geistige Krafte," since the operation of these forces preponderates over 

 the raw saps that form the leaves. And, finally, Goethe develops a theory of 

 germination, according to which the seeds and the leaf-buds are compared. 

 Goethe himself admits that his metamorphosis work does not contain any 

 really original observations; the metamorphosis theory itself occurs in 

 Linnasus's Philosopbia botanica, in which, under the heading " Metamofphosis 

 vegetabilis," the bud, the leaf, and the flower are analysed and the leaves in 

 their various transformations identified. Goethe, who admits that he had 

 read that work, nevertheless claims to have "discovered metamorphosis"; 

 by this he cannot reasonably mean anything else than its philosophical 

 side — the theory of the ideal type, according to which the leaves are trans- 

 formed. The "Geistige" that so frequently recurs in the treatise on metamor- 

 phosis is explained by the fact that it was this that Goethe considered to be 

 the essential, as also did Herder, of whose theory the plant-metamorphosis 

 doctrine is most reminiscent. For it is romantic philosophy from beginning 

 to end; it bears no resemblance whatever to modern natural research. 



His theory of colours 

 It was in the course of his journey to Italy, as a result of the impression made 

 upon him by the southern vegetation, that Goethe first had the idea of his 

 metamorphosis theory. During the same journey he had also studied, in 

 company with some artists in Rome, the laws of colour-combination and its 

 effect upon the sight. Not content with the results obtained in this respect, 

 he resolved upon his return home to devote himself to the study of colours 

 from the physical point of view as well. He procured a prism and with its 

 aid studied a number of light and colour phenomena. These he described 

 with great lucidity and accuracy in a work entitled Beitrdge %ur Optik, pub- 

 lished in 1791. He had, however, made one or two observations — that the 

 centre of a large white surface viewed through a prism remains white and 

 that a black line on a white ground is resolved by the prism into colours — 

 which he considered it impossible to explain by the Newtonian laws of 

 optics. It is true, some physicists in the piofession who read his book ex- 

 plained the phenomena to him in the light of Newton's theory, but Goethe 

 does not appear to have been much edified by it. Then Schelling took up the 

 question. As mentioned above, to him light represented the "absolute 

 identity," and he enthusiastically hailed Goethe as a liberator from New- 

 ton's detestable spectral theory. The poet, who was extremely sensitive to 

 applause as well as to criticism, was thereby entirely won over to the new 

 natural philosophy and felt encouraged to go on with his optical investiga- 

 tions in the hope of creating a new "colour theory" in place of Newton's. 

 After years of preparation he finally (in 1808) published his Farbenlehre — 

 the greatest of his scientific works and the one that he himself valued most 



