32 MUTANTS AND HYBRIDS OF THE OENOTHERAS. 



The seedlings of the last-named species show a wide divergence 

 in the juvenile leaves, which is partially continued even in the foliar 

 organs of the mature plant, although it is not believed that these 

 divergences may be grouped in separate strains of the species. Con- 

 sequently several selections were made from the cultures which, how- 

 ever, were soon found to be well within the limits of the type. 



The results obtained from 0. lamarckiana were of much greater 

 interest. Mutants were found in the seedlings grown directly from 

 the seeds from the garden at Amsterdam, and also from those of 1904 

 from the New York Botanical Garden. As early as October 1, 1904, 

 0. albida, 0. elliptica, and O. scintillans were recognizable in the plant- 

 lets grown from seeds produced in New York and Amsterdam. 

 L,ater, gigas, nanella, oblonga, and subovata were found. In addition 

 to these seven known mutants which had been seen to originate 

 previously in Amsterdam, seven other forms could be distinguished 

 which could not be identified with any forms heretofore observed by 

 Professor De Vries or the authors. It is therefore justifiable to say 

 that so far as present information goes the range of mutability of the 

 parent-species has been extended under the conditions under which it 

 has been cultivated in America. A comparative examination of the 

 cultures in the two localities brings out the fact that the plants grown 

 in New York were much more vigorous and active than those in 

 Amsterdam, and the suggestion lies close at hand that whatever the 

 causes may be that induce changes in the qualities of a species, the 

 actual environment in which such mutative alterations ensue is one 

 that has a majority of the factors favorable to vegetative development 

 as well as to plentiful seed-production. The limited number of facts 

 brought to light by the mutation cultures certainly support the sug- 

 gestion in question, which, it is to be noted, is in direct opposition to* 

 the conclusion of Darwin that new types arise most plentifully in 

 response to adverse circumstances. 



In conjunction with the foregoing it is to be recalled that seeds of 

 O. lamarckiana obtained from Vilmorin-Andrieux et Cie., in France, 

 by De Vries, produced some O. nanella when sown in the botanical 

 garden at Amsterdam in 1899. (De Vries, 1903, p. 459.) 



It is to be seen, therefore, that O. lamarckiana. is still in a mutable 

 condition in various portions of its widely extended range. The 

 results of the more recent cultures made in the botanical garden at 

 Amsterdam leads, however, to the conclusion that O. lamarckiana has 

 lost the capacity for producing O. lata, laevifolia, and brevistylis. De 

 Vries also found that the capacity for mutability inherited by rubri- 



