452 PROCEEDINGS OF THE ACADEMY OF [1892. 



THE PHENOMENON OF FERTILIZATION IN THE FLOWERS OF 

 MONARDA FISTITLOSA. 



BY IDA A. KELLER, PH. D. 



Although a conspicuous flower aud an irregularly shaped corolla 

 are apt to lead one to suspect that these are particular adaptations 

 to aid in securing cross fertilization, yet on the other hand close 

 observations have shown that these characteristics do not always 

 imply the desire to attract insect visitors. Nor is the idea that 

 close fertilization is only resorted to when the arrangements made 

 to favor cross fertilization have failed in their mission, perhaps as 

 generally true as is often supposed. The discovery of fertilization 

 in the bud, recently described by Mr. Meehan in Malva rotundi- 

 folia tends to confirm this view. Here fertilization, as Mr. Meehan 

 has shown, takes place in the bud, and the case is not exactly as 

 described by Prof. Miiller, who says : " As examples of the count- 

 less ways in which plants revert to self fertilization in default of 

 sufficient insect visits, I may mention the folloAving: — In some 

 dichogamic flowers the stigmas curl back upon the anthers or other 

 parts which still retain some pollen," ^ and as an instance of this he 

 gives the flowers of Malva rotundifolia. But in the flowers of this 

 plant examined by Mr. Meehan, the deposition of pollen on the 

 stigma lobes and the formation of pollen tubes begin before the 

 stigma lobes are curled backward. 



Aside from those cases to which the term cleistogamic is partic- 

 ularly applied : those in which two forms of flowers are produced, one 

 form being small, odorless, inconspicuous and closed, in addition to the 

 ordinary large conspicuous flowers, which are also much less fertile, 

 numerous instances are known where fertilization takes place in the 

 unopened bud. The term cleistogamy might with equal propriety 

 be extended to all cases where fertilization takes place before anthe- 

 sis, even with the entire absence of any dimorphism, and will per- 

 haps in time be so extended. 



An interesting form showing such close fertilization is found in 

 the buds of the ordinary flowers of Monarda fistiilosa. The figures 

 of Plate XV represent diflTerent stages of the opening of the 

 flower. Beginning with Fig. A, the oldest flower represented, we 



iProf. Herman Miiller. The Fertilization of Flowers. Translated by D'Arcy 

 V. Thompson, p. 591. 



