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THE AMERICAN NATURALIST [Vol. XLVI 



tures as biotypes and which so far have held their char- 

 acters through two and three generations. (Enothera 

 biennis is much more rich in biotypes than 0. grandiflora 

 probably because it is more hardy and adaptive in its life 

 habits, growing over an immense geographical range and 

 under a great variety of climatic and soil conditions. It 

 is clear that any one who cared to give an extended 

 period to the study of 0. biennis could differentiate 

 scores of elementary species in the assemblage of forms 

 included under this name. 



Further acquaintance with 0. Lamarchiama has led me 

 to believe that under this name must be included a num- 

 ber of races. Excluding the more striking of the ' ' mutants ' ' 

 of De Vries, there still remain strains that differ from 

 one another in such characters as the size of buds and 

 flowers, relative height of the stigma, forms of the cap- 

 sules, tint of the foliage, etc., and these strains, when 

 selected and carried on in " pure lines ' ' hold their pecul- 

 iarities and are true biotypes, although the differences 

 between them may be so small as to have little or no taxo- 

 nomic value. We have then under 0. Lamarchiama a 

 diverse assemblage and no one will ever be able to prove 

 that any one type is identical with the original since the 

 account of the original and the herbarium material 

 available do not give the information necessary for a full 

 description. 



The types called Lamarchiana, as now cultivated, have 

 come down to us perhaps entirely from cultures of 

 Messrs. Carter and Company of London at about 1860, 

 but they have come down through diverse channels with 

 abundant opportunities for hybridization and that differ- 

 entiation that results from selection, conscious or other- 

 wise, on the part of gardeners. In the experimental 

 gardens we are working chiefly with the strains that have 

 passed through the hands of Professor De Vries, who, 

 however, began his work (about 1886) many years after 

 the plant had been in cultivation. This material of the 

 experimental gardens has then been subjected to a large 



