FIFTEEN- AND SIXTEEN-CHROMOSOME OENOTHERA MUTANTS 65 
flowering season of the flowers produced by two biennial Lamarcki- 
anas, and it was found that a larger percentage of the early, than 
of the late, flowers had 4+-rayed stigmas. 
Fig. 3. 0. Lamarckiana, plant No. 5958, C.S.H., 1909. Offspring of 0. La- 
marckiana, selfed. Photographed late in the season to show manner of branching. 
This seemed to be due to a tendency on the part of the first flowers 
of the stem and vigorous rosette and stem branches to have 4 +-, rather 
than 4-rayed stigmas, though flowers with 4-rayed stigmas were com- 
mon among the first, and flowers with 4+- were frequently found near 
the terminal portions of these parts. After the plants had bloomed 
a short time, it was found that the number of flowers having 4-rayed 
