Oenothera Lamarckiana, a Mutating Plant. 219 



more rapidly ; until the field was finally planted witli 

 forest trees. At the present day traces of the plant still 

 exist. 



A rapid multiplication of this kind during the course 

 of a relatively short period of time has often been con- 

 sidered as one of the conditions for the appearance of a 

 mutable period. This consideration led to a closer inves- 

 tigation on the spot, which confirmed the conclusion. 



The plant exhibited a high degree of fluctuating varia- 

 bility in all its organs and characters. It presented also 

 numerous variations of another kind, of which I shall 

 only mention fasciation^ and "pitcher"-like malforma- 

 tions.- Most of the plants w^ere biennials, but many were 

 annuals ; and a few lived three years, as in the case of the 

 beet. 



That I really had hit upon a plant in a mutable period 

 became evident from the discovery, which I made a year 

 later, of two perfectly definite forms which were imme- 

 diately recognizable as two new elementary species. One 

 of them was a short-styled form: 0. hrevistylis, which 

 at first seemed to be exclusively male, but later proved 

 to have the power, at least in the case of several individ- 

 uals, of developing small capsules with a few fertile seeds. 

 The other was a smooth-leaved form with much prettier 

 f,oliage than O. Lamarckiana and remarkable for the 

 fact that some of its petals are smaller than those of the 

 parent type, and lack the emarginate form which gives 

 the petals of Lamarckiana their cordate character. T 

 call this form O laevifolia:^ 



^ Over de erfelykheid der fasciatien. Kruidkundig Jaarhock Do- 

 donaea, 1894, P- 72. Cf. pp. 92-95. 



" Over de erfelykheid der syniisen. Ibid., p. 129. Cf. p. 165. 



' Both forms are described and, in part, illustrated by Prof. 

 Julius Pohl: Ueber Variationsweite der Oenothera Lamarckiana, in 



