VOLUME LXII _ NUMBER 4 
THE 
POTANICAL (GAZETTE 
OCTOBER 17916 
NEW DIMORPHIC MUTANTS OF THE OENOTHERAS 
Huco DEVRIES 
(WITH FIVE FIGURES) 
Among the previously described mutants of Oenothera Lamarck- 
tana Ser. there is a form which, although fertile with its own pollen, 
yields a dimorphic progeny. Some of the individuals exactly 
repeat the stature and characters of their parent, but others return 
to the type of O. Lamarckiana. Besides these, new mutants, 
especially O. oblonga, are relatively numerous. The two main 
types are produced in varying proportions, according to the indi- 
vidual cultures. The typical specimens may be as few as 10 per 
cent, or as numerous as 80 per cent. In most instances, however, 
they show a proportion of about 35~40 per cent. Considering the 
much smaller individual strength of the typical ones, as compared 
with the atavistic specimens, these figures may be regarded as 
indicating a splitting, ordinarily, into nearly equal parts. 
This inconstant mutant is O. scintillans. Exactly the same 
phenomenon of splitting has been observed recently in a number 
of new types. In the first place, in O. stenomeres mut. lasiopetala, 
described by Bartrett.? In the second place, it has occurred in 
my own cultures, among the new mutants of O. Lamarckiana, as 
well as among those of another American species, described under 
*The mutation theory. Chicago. 1909. Vol. I, p. 377; and Gruppenweise 
Artbildung, p. 257. 1913. 
? BARTLETT, H. H., Mutations of O. stenomeres. Amer. Jour, Bot. 2:100-109; 
See also 2:146. 945 
249 
