566 THE AMERICAN NATURALIST [Vol. XL VII 



these new forms are regarded by Stomps as ' 'mutants'' 

 in the De Vriesian sense in the belief that biennis and 

 cruciate have an identical germinal constitution, except 

 for factors that determine floral structure and, therefore, 

 with respect to other characters may be crossed as 

 though they were homozygous. Applying these con- 

 clusions to the problem of the status of (E. Lamarchiana, 

 Stomps reasons that since biennis mutates and since 

 biennis is an older species than Lamarchiana, it follows 

 that mutations among the Oenotheras are older than La- 

 marchiana and consequently the mutations of this spe- 

 cies can not be the result of hybridization. 



In a recent discussion (Davis, '13) of the conclusions 

 of Stomps I have taken exception to the assumption that 

 his biennis and cruciata have exactly the same germinal 

 constitution except for floral characters. This I can not 

 believe probable, for the reason that, whatever may be 

 the relation between the two species, they have certainly 

 had a long period of independence. Cruciata has never 

 appeared in the extensive cultures of the Dutch biennis 

 that have been grown by De Vries and Stomps, and there 

 is no experimental evidence that it has been recently de- 

 rived from the latter form. From my point of view 

 Stomps really made a cross between two species and ob- 

 tained two marked variants due to some germinal modi- 

 fication as a result of the cross. 



It seems to me fair to ask: "Why did Stomps find it 

 necessary to cross biennis and cruciata to obtain these 

 " mutants" biennis nanella and biennis semi-gig as? If 

 they have the same germinal constitution except for floral 

 characters, Why should not biennis alone or cruciata 

 alone give the " mutants"? There is no form of biennis 

 better known to the workers in the experimental gardens 

 than this Dutch plant. It is believed to have been on the 

 sand dunes of Holland since pre-Linnaean times and 

 Bartlett ( '13) has recently presented strong reasons for 

 believing the plant to be the form known to Linnaeus as 

 CEnothera biennis and consequently to be regarded as 



