New Species of Oenothera 521 



first summer. It would be of no special use to 

 enumerate them. The negative result does not 

 apply to the species as such, but only to the in- 

 dividual strain, which I collected and cultivated. 

 Many species, which are quite constant with us, 

 may be expected to be mutable in other parts 

 of their range. 



Only one of all my tests met my expectations. 

 This species proved to be in a state of mutation, 

 producing new elementary forms continually, 

 and it soon became the chief member of my ex- 

 perimental garden. It was one of the evening- 

 primroses. 



Several evening-primroses have at different 

 times been introduced into European gardens 

 from America. From thence they have spread 

 into the vicinity, becoming common and exhibit- 

 ing the behavior of indigenous types. Oenoth- 

 era biennis was introduced about 1614 from 

 Virginia, or nearly three centuries ago. 0. 

 miiricata, with small corollas and narrow 

 leaves, was introduced in the year 1789 by 

 John Hunneman, and 0. suaveolens, or sweet- 

 scented primrose, a form very similar to the 

 biennis, about the same time, in 1778, by 

 John Fothergill. This form is met with in dif- 

 ferent parts of France, while the biennis and 

 muricata are very common in the sandy regions 

 of Holland, where I have observed them for 



