igisl 



BARTLETT— MUTATION IN OENOTHERA 



121 



grains had accidentally reached the stigmas of the mother plants. 

 This hypothesis was tested by crossing 0. pratincola with 0. niimis- 

 matica. As ahead}' stated, these two species were the only Onagras 

 which the writer found at Lexington. The latter, furthermore, is 



Fig. 17. — Fi progeny of Le.xington G, pan 27, Oenothera pratincola; four mutations 

 are shown, G-so and G-53, mut. nibriceiitra; G-51, mut. nilida; G-52, mut. nuni- 

 mularia; the other plants are typical 0. pratincola. 



suspiciously similar in several characters to mut. nummnlaria. as 

 may be seen by comparing the characters already recorded. The 

 cross 0. pratincola 5X0. numismatica S was conspicuously fertile; 

 326 seeds from one capsule gave a culture of 222 plants, consisting 



