382 



THE AMERICAN NATURALIST [Vol. XLVI 



591). That an identification with Lamarckiana can ever 

 be made from the average herbarium sheet seems to the 

 writer almost impossible, for the specimens of CEnothera 

 formerly collected rarely give a fourth of the informa- 

 tion necessary to make a critical comparison with 

 Lamarckiana. With the clear evidence that the present- 

 day Lamarckiana holds a genetic relation to the cultures 

 of Carter and Company, about 1860, the problem of its 

 origin has become much more tangible than formerly 

 and this matter will be taken up in our discussion of these 

 cultures in relation to the sheet in the Gray Herbarium 

 at Harvard University. 



American botanists are not likely to believe that 

 Lamarckiana, if present in America in 1860, has become 

 so quickly extinct, knowing as they do the vitality of our 

 rich CEnothera flora. For example, 0. grandiflora has 

 actually persisted in the same locality since its first dis- 

 covery by William Bartram in 1776. Let those interested 

 in the problem of the status of Lamarckiana use their 

 best endeavors to discover this plant in the field, but let 

 them give us their results not only by herbarium material 

 covering the entire life history, but above all through seed 

 that can be sent to the workers in the experimental 

 gardens. 



The material of this paper will be arranged under the 

 following headings: (1) Methods, (2) Large- and Small- 

 flowered Biotypes of CEnothera Lamarckiana, (3) Further 

 Races of CEnothera biennis L., (4) Further Races of 

 CEnothera grandiflora Ait., (5) Hybrids in the F x Gener- 

 ation from the Cultures of 1911, (6) Hybrids in the F 2 

 Generation from the F t Hybrid Plants 10.30La, and 

 10.30 Lb, (7) The Probable Composition of the Cultures 

 of Carter and Company from Evidence Furnished by the 

 Sheet in the Gray Herbarium, (8) Further Considera- 

 tions on the Possible Origin of CEnothera Lamarckiana 

 as a Hybrid of 0. biennis and 0. grandiflora. 



As in previous seasons, I am greatly indebted to the 

 Bussey Institution and to the Botanic Garden of Harvard 



