278 



GENETICS IN RELATION TO AGRICULTURE 



from its base so as often to form a dense bush. These branches in their turn have 

 numerous lateral branches. Most of them are crowned with flowers in summer, 

 which regularly succeed each other, leaving behind them long spikes of young 

 fruits. The flowers are large and of a bright yellow color, attracting immediate 

 attention, even from a distance. They open toward evening, as the name in- 

 dicates and are pollinated by bumblebees and moths. Contrary to their con- 

 geners they are dependent on visiting insects for pollination. (E. biennis and 

 (E. muricata have their stigmas in immediate contact with the anthers within 



Fio. 115. Leaf, flower bud, flower and essential organs of CEnothera rubrinervis (14) 

 and (E. bretistylis (5-8). The specimen of brevistylis came from a red pigmented 

 strain grown by Dr. R. R. Gates; the original brevislylis had no more red pigment than 

 lamarckiana. 



the flower buds, and as the anthers open in the morning preceding the evening 

 of the display of the petals, fecundation is usually accomplished before the insects 

 are let in. But in (E. lamarckiana no such self-fertilization takes place. The 

 stigmas are above the anthers in the bud, and as the style increases in length 

 at the time of the opening of the corolla, they are elevated above the anthers 

 and do not receive the pollen. Ordinarily the flowers remain sterile if not 

 visited by insects or pollinated by myself, although rare instances of self-fertiliza- 

 tion were seen .... Ordinarily biennial, it produces rosettes in the first, 

 and stems in the second year" (de Vries). 



De Vries' original discovery consisted of the location of two aberrant 

 groups among several thousand lamarckiana individuals. One of these 

 new forms had smooth leaves and was named kevifolia, the other had 



