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6. METAMORPHOSIS. 



It was C. F. Wolff who was tlie first to hint at the 

 origin of the flower as being the outcome of a gradual 

 metamorphosis of the foliage-leaves situated at a lower 

 level on the axis of the plant. He held that the pro- 

 duction of floral leaves was the result of a degenera- 

 tion in the quality of the sap, the richer portion being 

 used up at a lower level by tlie first-formed vigorous 

 foliage-leaves. The great German poet Groethe, how- 

 ever, first established the theory of the underlying 

 homology of all foliar organs of the plant. His main 

 idea was that the floral leaves i^epresent the final stage 

 in a gradual ascending metamorphosis of which the 

 foliage-leaves are the starting-point, and that the pro- 

 duction of flowers is due to an' improvement and 

 etherealization of the sap during its ascent through 

 the plant, all foliar organs being variants on an ideal 

 type-leaf. This conception was probably the best that 

 could be framed at a period when our modern idea of 

 descent with modification from some one primitive 

 form was conspicuous by its absence.. These two great 

 thinkers dealt solely with the individual development 

 of the plant ; they, like so many biologists since their 

 time, failed to see that this could throw no real light 

 upon the ultimate phylogenetic development of the 

 parts concerned. Groebel holds that any foliar organ 

 of a flower, whether sepal, petal, stamen, or carpel, is 

 a modification or transformation of a rudiment, which 

 itself is always of the nature of a foliage-leaf. Cela- 

 kovsky derived both perianth- and foliage-leaves from 

 sporophylls. 



The majority of modern botanists hold that the 

 process during the evolution of the race has been 

 that which "Wolff and Goethe set forth, although these 

 writers had an eye on the process of individual develop- 

 ment only ; viz., that the flower as we know it in the 



