MUTATIONS OF OENOTHERA SUAVEOLENS DESF. 



253 



In 1915 1 crossed three specimens of my mutant with the species 

 and made one reciprocal cross. The harvest was only a small one, 

 but the results were very clear. I counted the progeny in June and 

 July at the time when the characters were most sharp and found: 



The characters of Oe. mut. fastigiata were handed down through 

 the egg cells and not through the pollen, exactly as in the case of 

 Oe. mut. lutescens. Moreover the high degree of mutability of Oe. 

 mut. fastigiata was inherited in the same way, showing a curious 

 correlation between the visible and the invisible characters. 



A very conspicuous mark of Oe. mut. fastigiata is seen in the 

 rosettes of the radical leaves. These are bent downward and pressed 

 with their tips against the soil, whereas in Oe. suaveolens and in 

 Oe. mut. jaculatrix they are straight and erect. This makes the 

 rosettes of Oe. mut. fastigiata very dense, but those of the two 

 other forms loose. 



(6) Oe. suaveolens mut. jaculatrix (fig. 3) 



Throughout the whole evolution the leaves of this form are almost 

 linear, but with a long and sharp tip. They are dark green and in 

 vigorous specimens sufficient for the nourishment of the plant; 

 in weak ones, however, often deficient in this respect. The stature 

 is always very low, seldom exceeding half a meter at the time of 

 flowering. The flowers are small, the petals narrow, 'eaving gaps 

 between them. Their size is 15 x 20 mm. against 30 x 30 mm. in 

 the species. The fruits are short and thick and pressed against the 

 axis; they yielded ordinari'y only a small supply of seeds. I suc- 

 ceeded in self-fertilizing only three specimens in 1915; they gave 

 3, 7 and 6, together 16 offspring, of which 7 were jaculatrix, 3 fasti- 

 giata and 6 lutescens. No pure suaveolens was seen among them. 

 This indicates constancy of the type combined with a high degree 

 of mutability, just as we have seen in Oe. mut. fastigiata. 



I have not succeeded in making fertile crosses of the mutant with 

 the species. 



