Chap, u i The Morphology of the Flower 87 



the contrary direction as the older dogma claimed. From 

 this view it was no great step to regard the flower as primarily 

 composed of sporophylls, by sterilization of which the 

 members of the perianth became differentiated. 



A somewhat similar idea, but one of much less general 

 application, had already been advanced by Prantl, when 

 he made the suggestion that the petals in certain Ranun- 

 culaceous flowers have been derived from abortive stamens. 

 It was left, however, to Bower to put forward the great 

 generalization on which the study of floral morphology 

 depended during the remaining years of the century. 



Among contemporary writers Goebel gave a modified 

 adhesion to Bower's view, but denied that its application 

 was so general as had been claimed. He argued that the 

 converse metamorphosis must not be excluded, for that in 

 such flowers as those of the Nymphaeaceae the leaves of 

 the flower are demonstrably derived from bracts. In certain 

 anemones he claimed to be able to trace the transformation 

 of the involucre to the calyx, and its gradual assumption of 

 petaloid characters subsequently. 



The question of the nature of the metamorphosis — 

 whether it had been progressive or regressive— led to con- 

 siderable discussion as to the nature of the primitive flower 

 of the Angiosperms, and the controversy was maintained 

 long after the close of the century. There were two main 

 schools of thought : the first saw with Engler such a 

 primitive flower in the forms with one or more free sporo- 

 phylls without any perianth, and traced its development 

 by modification of this type, by such steps as the gradual 

 differentiation of a perianth, by the further differentiation 

 of the sporophylls into stamens and carpels, and by 

 modifications of the arrangement of all, together with 

 congenital unions between the members of the whorls 

 of each and between them and the floral axis : the 

 other school, on the whole under the inspiration of 



