752 THE AMERICAN NATURALIST. [Vol. XXXV II. 



experimental material was derived were sown in a bed at s' Grave- 

 land near Amsterdam in 1875 and had been allowed to spread 

 over an adjoining neglected field until in 1884 an area of 2800 

 square meters was covered. This material showed the presence 

 of a form so different from the parent type, when examined by 

 deVries in 1886, as to lead him to consider it as a new species, 

 and this mutant, CE. bre%nstylis, which did not arise again during 

 the observations, maintained itself in the same locality during a 

 period of twelve years, records of it having been made as late as 

 1898, and it is still cultivated among the other mutants grown 

 by deVries and myself. Other forms appeared during the 

 course of the next fourteen years as has been described in detail. 

 It was deemed advisable to make independent comparisons of 

 the plants grown in my own cultures with the type specimen 

 with which deVries identified his parent form, and to this end 

 Miss A. M. Vail made a visit to the herbarium of the Museum 

 d' Histoire Naturelle in Paris, in May, 1903, at my request, and 

 also later a journey to Amsterdam and inspected the cultures 

 of OiiwtJicm under Professor deVries's own guidance. Miss 

 Vail has kindly prepared the following report on the matter : 



"The parent form, CEnothera lamarckiana Ser. was found by 

 deVries to agree in every particular with two specimens in the 

 Museum d' Histoire Naturelle in Paris. These specimens con- 

 sist of, first : a plant cultivated in the Paris Garden that had 

 formed the basis of the original description of CEnothera gmnd- 

 iflora Lam. It bears a label indicating it as having been 

 included in the herbarium of Lamarck which was acquired by 

 the Museum in 1850. On the margin of the sheet in the hand- 

 writing of Poiret (the author of the section dealing with CEno- 

 thera in Lamarck's Encyclopedia) is the following inscription 

 'CEnothera — (grandiflora) — nova spec, flores magni lutei, odore 

 grato, caulis 3 pedalis.' This specimen is in flower only and 

 consists merely of the branched upper portion of the shoot with 

 numerous rather small leaves and conspicuously large typical 

 flowers. The second specimen comes from the collection of 

 Abbe Pourret that was contained in the collections of Dr. 



1 For a brief general account of the e.xperimental cultures, see MacDougal, The 

 Original of Species by Mutation. Torreya, Vol 2, pp. 65-6S, 81-84, 97-100. 1902. 



