CHAPTER XVI 



TRUE NATURE OF FLORAL ORGANS; DETAILS OF 

 THEIR STRUCTURE; FERTILIZATION 



188. The Flower a Shortened and greatly Modified 

 Branch. — In Chapter IX the leaf-bud was explained 

 as being an undeveloped branch, which in its growth 

 would develop into a real branch (or a prolongation of 

 the main stem). No^v, since flower-buds appear regularly 

 either in the axils of leaves or as terminal buds, there is 

 reason to regard them as of similar nature to leaf-buds. 



Fig. 117. Transition from Bracts to Sepals in a Cactus Flower. 



Tliis would imply that the receptacle corresponds to the 

 axis of the bud shown in Fig. 55, and that the parts of 

 the flower correspond to leaves. There is plenty of e-^-i- 

 dence that this is really true. Sepals frequently look 



159 



