252 



PLANT-BREEDING 



They open half a day before the petals expand the flowers 

 and invite the insects to a visit. During these last hours, 

 within the closed bud fertilization usually takes place, and 

 all is over before the insects come, insuring in this way a 



Fig. 78. Flowers of Evening Primroses, deprived of the petals. A. 

 The ordinary species, {Oen. biennis), a self-pollinating species, collected 

 near Chicago. B. Summer-flower of Lamarck's Evening Primrose, the 

 stigma protruded beyond the anthers. C. A late flower of the same plant 

 with the anthers touching the stigma. 



most complete self-fertiHzation. Often I have seen the 

 buds drop off before opening without the least detriment to 

 the ripening of the fruit. In other cases I succeeded in 

 cutting away the buds about an hour before their time for 

 opening, but the young fruits had already been fertiUzed 



