On atavistic Variation in Oenothera cruciata 



By Hugo de Vries 



After Oenothera Lamarckiana had shown itself to be a very- 

 proper material for the study of the mutations by which new 

 species suddenly arise from old ones, I was naturally led to in- 

 vestigate whether in other plants similar mutations might not be 

 met with. For it is clear that the phenomena shown by Lamarck's 

 evening primrose are of prevailing interest only if they may be 

 taken as an instance of a general rule. The other species of the 

 same genus were of course the first to receive attention. Most of 

 these showed no signs of being fit for a study along the same lines, 

 while on the other hand one, Oenothera cruciata, was found to be 

 inconstant in the very character to which it owes its name. At 

 least the plant which is cultivated under this name in European 

 botanical gardens is variable in this regard. 



In proposing to bring the results of my experimental cultures 

 of this plant before the readers of this journal, my aim is principally 

 to direct their attention to any deviations which the species of the 

 above-named genus might show in' their native localities. For it 

 is of undoubted interest to the study of mutability to know whether 

 the variability which Oenothera cruciata displays with us is also 

 met with in America, in those parts where the plant grows wild. 

 The allied forms such as 0. biennis and 0. muricata, should be 

 tested in the same direction. Any deviations from the original 

 types should be carefully observed and if possible perpetuated 

 by seeds. Wherever such deviations are found the question would 

 have to be answered whether the general type of the locality pos- 

 sesses the power of again producing this deviation, and perhaps 

 others too, in succeeding years. 



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