1915] BARTLETT—MUTATION IN OENOTHERA IIg 
of mistaking mut. nummudlaria for the parent type or for one of the 
other mutations is negligible. The orbicular seedling leaves are 
too striking a characteristic to be overlooked. 
of 
Leemgror C-Y/ far@ 
0 om 
Fic. 15.—F, progeny of Lexington C, Oenothera pratincola (pan 6 of the progeny 
ot C-91); one plant of mut. xummularia is shown. C-91-4; the other plants are typical. 
The unlikeness of mut. nummularia and O. pratincola < O. 
numismatica 
Before mut. nummularia had been found in F, progenies from 
guarded seed, it seemed possible that it might be an F, hybrid of 
QO. pratincola with some other wild species, of which a few pollen 
