260 PRINCIPLES OF PLANT-TERATOLOGT. 



There is the interesting example of a garden tulip 

 {Tulipa Qesneriana) observed by Roeper, in which, 

 obviously owing to the carpelloid transformation of 

 the inner whorl of stamens, the normal carpels had 

 become suppressed. This explanation is more probable 

 than that the inner whorl of stamens was suppressed 

 and the carpels had become rearranged in order to 

 alternate with the stamens of the outer whorl. 



GBNBEAL CONCLUSIONS. 



The majority of botanists in the past have subscribed 

 to the view that the pleiomerous condition of the flower 

 is the more recent, the oligomerous the most primitive 

 phenomenon in any given order or group of plants. 

 For example it was held that in the Cruciferae the 

 dimerous condition was the original one from which 

 the pleiomerous condition (as in the androecium) of 

 other genera and of Capparidace* was derived by 

 ■fission of the stamens. This view appears to have 

 been based largely on the facts of ontogeny observed 

 in such orders as the Cistinese and Hypericacese, in 

 which the groups of numerous stamens were each seen 

 to branch from a single rudiment. Protagonists of this 

 view are De CandoUe, Bichler, Delpino, Bugler, and 

 Velenovsky. In recent years, however, what is pro- 

 bably the more rational view has been set forth, mainly 

 by Celakovsky, that the opposite is true, namely that 

 the pleiomerous condition is the more primitive of the 

 two. So that a flower like that of Galycanthus or 

 Nympheea, with numerous members in all the whorls, 

 would stand for the most primitive type. Two main 

 facts are strongly in favour of Celakovsky's view : 

 firstly, that many orders, for other reasons regarded 

 as primitive, often have pleiomerous sexual whorls, 

 the members being arranged in spiral series, e. g. 

 Ranunculacese, Nympheeacese, Magnoliacese, and Pal- 

 macege ; secondly, that the process of reduction is so 

 widely observable as having occurred in the past that 



