150 CARROLL— ON DEVELOPMENT OF 



In several of the rather small number of experiments, these flowers 

 produced good seed. This would indicate that self-pollination had 

 occurred before the removal of the stamens. How far this self-polli- 

 nation before the opening of the bud occurs in nature would be difficult 

 to determine. There is no indication of the occurrence in the behavior 

 of the flower. The castrated flowers were normal chasmogamous flowers 

 to all appearances. Apparently they would have opened their sepals 

 and petals within another day. In the Hght of the possibiUty of self- 

 pollination at this stage and the subsequent opening of the sepals and 

 petals, one could not say with certainty whether a particular flower 

 was poUinated before or after it opened. 



Pollination and Fertility of cleistogamous and chasmogamous Flowers 



References occur in the Hterature to a lack of agents of pollination 

 and to a high degree of sterility among the chasmogamous flowers of 

 / fulva. Bennett (4) says "the conspicuous flowers are stated by all 

 observers to be usually barren." This does not agree with my own 

 observations. It is quite true as Gray states (18) that "many of the larger 

 and fully developed flowers fall away without forming fruit." In one 

 large group of plants under observation, not one chasmogamous flower 

 was observed to produce fruit. Yet the abundant production of fruit 

 from chasmogamous flowers was elsewhere evident. A large number 

 of flowers were marked with tags and observations carried through till 

 the collection of seed. Bennett thinks the arrangement of stamens 

 and pistils is such as to prevent self-pollination, yet equally adapted to 

 prevent cross-pollination. The filaments send out from their inner 

 faces broad processes which are connivent over the pistil in such manner 

 as to prevent any pollen from the anther reaching the pistil. The whole 

 whorl of anthers later falls away together, exposing the stigma. Bennett 

 states that he has never observed this to take place spontaneously, 

 but that the flower drops as a whole carrying the pistil along. This 

 phenomenon frequently occurs, but it seems to be an abnormal occur- 

 rence. Normally the whorl of stamens falls away exposing the pistil. 

 The petals and sepals fall several hours to a day later. The falling 

 away of the flowers with the pistil included, observed by Bennett on the 

 Wey may be associated with conditions of a foreign home. Under 

 adverse conditions in America the same process occurs. One group 

 of plants, nearly denuded of foliage by insects, showed this phenomenon 

 and similar instances were observed in dry weather. 



