88 



White. 



A detailed study of the various whorls disclosed many more 

 anomalous characters. The calyx, in addition to being irregular, 

 sometimes possessed a sepal attached to the outside of the regular whorl 

 (Fig, 12). Sepal lobes were irregular in size, and occasionally one would 

 occur with a slight reddish color on the tip (calycanthemy). Calyx and 

 corolla whorls not uncommonly were present as one spiral whorl 

 („speiranthie"). Two flowers were sometimes fused and enclosed in a 

 continuous calyx (adhesion). Once or twice, a flower was found con- 



Fig. 12. Stems and flowers of the fasciated 

 (300—309) and normal (402) races of N. tabacum. 



sisting of only a corolla and a few stamens, growing on the side of 

 and fused with the main corolla (synanthy). Instead of an increase in 

 flower parts through a multiplication of whorls (pleiotaxy) the increase 

 takes place through a multiplication of the number of parts per whorl 

 (polyphylly). All four whorls are increased in the number of their parts 

 in this manner. Polyphylly of the androecium increases the number of 

 stamens per single flower, the range of variability being 4 — 25. 

 Filaments are fused to each other (cohesion) and to the walls of the 

 corolla (adhesion). The anther-sacs are sometimes split at the end into 



