140 



PRINCIPLES OF PLANT-TERATOLOGY. 



Caspary observed in several species of the white 

 water-lily (Nymphsea) that the bract supplying the 

 place of the anterior sepal, along with the two lateral 

 sepals, became displaced downwards on to the peduncle, 

 leaving .only the single posterior sepal over for the 

 flower. As a result of this and to supply a fresh calyx, 

 the four diagonally-placed petals of the first whorl 

 became transformed into sepals. 



Celakovsky aptly points out that the flower of 

 Ni/mphdea is one of the best for showing how, by means 



Fig. 119. — Pyrus Mains (Apple). Petals transformed into sepals, each 

 with a fleshy base (= segment of apple- flesh). 



of the excellent transitions which exist, the petals are 

 all derived from stamens. In Caspary 's abnormal 

 flowers, therefore, we have a good instance of how 

 sepals also ultimately have the same origin as petals, 

 viz , from the stamens. 



The origin of a whorl of sepals from a corolla- whorl 

 as a normal process is most admirably exhibited by 

 the Crucifera? ; as Celakovsky points out, the inner 

 (transverse) calyx-whorl has here been derived by 

 metamorphosis from the outermost corolla- whorl of the 

 Papaveracese. For the Cruciferge are a more recent, 

 derived type than the Papaveracea3, which come 



