THE ORIGIN OF THE "FLOWER" 



By W. C. WORSDELL, F.L.S. 



A typical flower, such as a buttercup, consists of a central 

 conical disc or receptacle on and around which are seated 

 four distinct sets or groups of floral organs ; the outermost 

 set of five green leaves is the calyx, the second whorl of brilliant 

 yellow leaves is the corolla ; then follow in succession a large 

 number of scattered stamens, or a few arranged in a whorl, and 

 finally a (usually) corresponding number of carpels (the seed- 

 bearing organs). 



If we carefully dissect a flower, and examine all its parts, 

 it becomes clear that in a flower we are concerned not with 

 something entirely new and distinct from every other part of 

 the plant, but merely with a modification of an ordinary leafy 

 shoot ; for the central disc is a highly contracted and shortened 

 shoot ; the sepals, petals, stamens, and carpels are all leaves 

 which have been in various degrees modified and altered to 

 suit the specific functions which they have to perform in the 

 economy of the plant's life. It was Caspar Friedrich Wolff 1 

 who was the 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 plant. He held that the pro- 

 duction of floral leaves was the result of a degeneration in the 

 quality of the sap, the richer portion being used up at a lower 

 level \>y the first-formed vigorous foliage-leaves. Goethe, 2 

 however, first established the theory of the underlying homo- 

 logy of all foliar organs of the plant. His main idea was that 

 the floral leaves represented the final stage in a gradual ascend- 

 ing metamorphosis of which the foliage-leaves are the starting 

 point, and that the production of flowers is due to an improve- 

 ment and etherealisation of the sap during its ascent through 

 the plant. All foliar organs, he said, are variants on an ideal 



1 Theoria gcnerationis, 1759. 



2 Versuch die Metamorphose der Pflanzeti zu erkldren, Gotha, 1 790 (Essay on 

 the Metamorphosis of Plants, translated by Emily M. Cox in Seemann's Journal 

 of Botany, vol. i. 1863). 



255 17 



