A Branch of the Lamarckiana-Fainily. 259 



bility of Oenothera Lamarckiana. But inasmuch as ex- 

 perimental investigation of other instances has not yet 

 been pubHshed, we must, pending the acquisition of that 

 knowledge, regard it as a typical case of the origin of 

 new species. 



§ 5. A BRANCH OF THE LAMARCKIANA-FAMILY. 



In 1895 I started a culture which may be res^arded 

 as a branch of the main line of descent which has already 

 been described. My object was to try to get more muta- 

 tions by increasing the sowings. I used the seed which 

 had been harvested in 1889, a part of which had already 

 been employed in the culture summarized on p. 224. 

 The available quantity of seed amounted to about 230 

 ccm. and was all sown. 



In November 1888 I picked out from among the 

 plants that I had saved during the summer the 12 strong- 

 est; and planted them on a separate bed where the con- 

 ditions were very favorable owing to the fact that the 

 position was a sunny one, and that it was far away from 

 any other Oenothera cultures. In the spring of 1889 I 

 reduced the number to 6, which grew up to fine well- 

 branched plants. Each plant flowered not only on its 

 main stem and its branches but also on the numerous 

 branches which sprang from the axils of the radical 

 leaves. Superfluous lateral branches were however cut 

 away in July. Each plant furnished from 25-50 ccm. 

 of seed and the seed from separate plants was harvested 

 separately. The pollination of the flowers, which were 

 not enclosed, was left to insects. I sowed the seed as 

 evenly as possible on a bed of 12 square meters, kee])ing 

 the seed of the 6 seed-parents in separate lots. As soon 



