60 



THE AMERICAN NATURALIST 



[Vol. XLIX 



is a very important contribution for there have been some changes 

 in the mounting of important specimens in the herbarium of 

 Lamarck since the first studies by De Vries in 1895 and it was 

 not clear what material formed the subject of his discussion in 

 "Die Mutationstheorie. " As the result of this second examina- 

 tion (1913) there can be no misunderstanding of De Vries 's 

 conclusion as to what represents the type of (Enothera Lamarck- 

 iana Seringe, and we have also very positive opinions on the 

 identity of other interesting material in the collections at Paris. 

 Thanks to his descriptions and photographs of these sheets further 

 confusion will be impossible and botanists may now make for 

 themselves the observations that will in the end determine their 

 judgment of the soundness of Professor De Vries 's views and of 

 the value of the exceptions that may be taken to them. 



I shall not at this time discuss in detail the queries which pre- 

 sented themselves on my reading of De Vries 's paper. The most 

 important of the points probably rest on facts that should be 

 shown by the material, but which have not been published in the 

 account of De Vries. I expected to have the data in question this 

 autumn but the European disturbances have necessarily upset 

 my plans and it may be very many months before I can take up 

 the matter. 



However, I will briefly say that De Vries 's identification of 

 the sheets under consideration are to me not convincing chiefly 

 for the following reasons. His account gives no description of 

 the pubescence of the sepals, stems, or capsules when present. 

 Yet pubescence is a character of great importance in the descrip- 

 tion of many species of (Enothera. To illustrate the point, all 

 races of 0. grandiflora Solander that I know have sepals and 

 capsules almost glabrous or very sparsely pilose and puberulent. 

 Lamarckiana on the contrary presents sepals and capsules with 

 a very heavy puberulent and pilose pubescence. Should any of 

 the specimens at Paris which De Vries has identified with the 

 Lamarckiana of his cultures present sepals or capsules lacking 

 the heavy pubescence of this plant the fact to me would be very 

 strong evidence that his identification was incorrect. 



There are two sheets under consideration as standing for the 

 type of Oenothera Lamarckiana Seringe. De Vries regards one 

 as unequivocally representing the type specimen. I have for 

 various reasons placed the greater emphasis upon the other. 

 Both specimens as shown in photographs appear to have essen- 

 tially the same features as to their general morphology. Miss 



