690 



THE AMERICAN NATURALIST 



[Vol. L 



On the other hand, various races of Lamarckiana are at present 

 growing wild in a number of English localities, the best known 

 stations being on sand hills of Lancashire near Liverpool. A 

 conspicuous Oenothera flora was present in this region as early 

 as the beginning of the nineteenth century, as shown by an ac- 

 count in Smith's " English Botany," 1806. There seems to be 

 no reason why Oenothera Lamarckiana might not have arisen in 

 such a locality as a hybrid of species introduced into England 

 possibly through Liverpool as a port of entry. Thus we are 

 dealing with dates of introduction or origin that are reasonably 

 close to present times; attempts to associate Lamarckiana with 

 very early introductions into Europe appear no longer to have 

 important support. 



It is necessary to bear in mind this historical setting, since it 

 may seem to my readers very improbable that CEnothera La- 

 marckiana should have arisen as a hybrid between franciscana, 

 a species of western America, and biennis of Holland, England 

 and other European countries. There is, however, nothing im- 

 probable in the possible meeting at Liverpool, with its world- 

 wide commerce, of species of CEnothera from far corners of the 

 earth. Furthermore, I should be the last to suggest that the 

 particular races or species which give my neo-Lamarckiana have 

 been the actual parents of the strains of Lamarckiana cultivated 

 by De Vries. To strike the identical parental lines of such an 

 assumed hybrid would in the case of the Oenotheras be a most 

 extraordinary piece of luck. It is remarkable that my results 

 have proved so satisfactory; I have no doubt that other species 

 crosses may sometime be made which will give hybrids as close 

 or even closer to Lamarckiana. 



The line of neo-Lamarckiana, which I now have in the F 4 

 generation from the original cross, was derived from a single 

 selfed plant in the F 2 (14.53c), which fell well within the range 

 of variation given by De Vries for CEnothera Lamarckiana. A 

 description will later be published of this plant together with an 

 account of its progeny through successive generations when these 

 have been carried along somewhat further. The F 3 generation 

 gave very few neo-Lamarckiana types, but these were closer to 

 the large-flowered forms of De Vries 's cultures. This F 3 gen- 

 eration was grown from earth-sown seeds and incomplete germi- 

 nation may have been responsible for the small proportions of 

 neo-Lamarckiana, 7 in a total of 291 plants. The F 4 generation 



