TtiE ANbRCECIUM 



181 



retrograde metamorphosis occurs, the stamens changing into 

 petals with consequent development of double flowers. In 



FIG. 110. St. John's Woert (Hypericum sp.) showing progressive meta- 

 morphosis. 



FIG. 111. White water lily showing retrograde metamorphosis, the stamens 

 changing into petals. 



many flowers one set of stamens has been aborted so that 

 only one circle remains. 



