iv] THE FLOWER AND METAMORPHOSIS 57 



then the origin of the Flower, and particularly of 

 those sporangial organs which are its distinctive 

 feature, cannot have been an afterthought. They 

 cannot ever have been superposed upon a pre- 

 existent vegetative system. And this must still be 

 true notwithstanding that in the life of any ordinary 

 plant the vegetative leaves appear first. The Flower 

 cannot have been a mere result of metamorphosis of 

 a vegetative shoot, for it represents a phase which has 

 grown up together with the rest of the plant, and has 

 been an integral part of its completed life through- 

 out descent. Those who realised this to the full were 

 at first disposed to invert the theory as stated by 

 Goethe and his followers. Instead of holding that 

 the flower was really a vegetative shoot adapted for 

 propagative duties, they were disposed to assume that 

 the whole plant had originally been propagative, and 

 that the vegetative system had originated by sterili- 

 sation of certain of its parts. It was suggested that 

 such sterile parts were then told off to purposes of 

 nutrition as a new duty. Moreover, experimental 

 evidence from the Ferns seemed to tend directly 

 towards this conclusion, for it was found possible 

 experimentally to transform fertile leaves of Ferns 

 into sterile leaves, with abortion of the sporangia. 

 This seemed essentially parallel with the transforma- 

 tion of stamens into petals, or carpels into green leaves, 

 as is seen in some " doubled " flowers. 



