Experimental Pedigree-Cultures 575 



suit the requirements of the new species ruhri- 

 nervis and gigas. 



Note. — Oenotheras are native to America and all 

 of the species growing in Europe have escaped from 

 gardens directly, or may have arisen by mutation, or 

 by hybridization of introduced species. A fixed 

 hybrid between 0. cruciata and 0. biennis constituting 

 a species has been in cultivation for many years. 

 The form known as 0. biennis in Europe, and used 

 by de Vries in all of the experiments described in these 

 lectures, has not yet been found growing wild in 

 America and is not identical with the species bearing 

 that name among American botanists. Concerning 

 this matter Professor de Vries writes under date of 

 Sept. 12, 1905: "The 'biennis' which I collected in 

 America has proved to be a motley collection of forms, 

 which at that time I had no means of distinguishing. 

 No one of them, so far as they are now growing in 

 my garden is identical with our biennis of the sand 

 dunes." The same appears to be the case with 

 0. muricata. Plants from the Northeastern American 

 seaboard, identifiable with the species do not entirely 

 agree with those raised from seed received from 

 Holland. 



0. Lamarckiana has not been found growing wild 

 in America in recent years although the evidence at 

 hand seems to favor the conclusion that it was seen 

 and collected in the southern states in the last century. 

 (See MacDougal, Vail, Shull, and Small. Mutants 

 and Hybrids of the Oenotheras. Publication 24. 

 Carnegie Institution. Washington, D. C, 1905.) 



Editor. 



