398 Origin of Each Species Considered Separately. 



The third plant of 1895 set little seed and only gave 

 rise to 27 seedlings not one of which was an elliptica. 



The mutant of 1896 was an extraordinarily beautiful 

 plant with narrow leaves and narrow elliptical petals, and 

 altogether absolutely unlike an ordinary Oenothera. Its 

 fruits were long and thin and contained but few fertile 

 seeds. 32 seeds germinated; 27 of the plants they gave 

 rise to were O. Lamarckiana, the remaining 5 were 0. 

 elliptica — that is about 15 %. These five plants devel- 

 oped stems, but did not flower till November : they were 

 exactly like their parent. Their leaves did not exceed 

 2-3 cm. in breadth, the petals were elliptical and without 

 the emargination at the tip. They did not set seed. 



The last mutant which bore seed was a plant which 

 arose in 1899 from seed of 0. scintillans. It appeared 

 in the culture of 5850 rosettes (p. 388) which gave 40 % 

 O. scintillans in the third generation. This culture con- 

 tained only one 0. elliptica, which, as it was transplanted 

 early, grew up into a plant which branched profusely 

 and flowered freely but was of rather low growth. Its 

 leaves were very narrow but its flowers relatively large. 

 The breadth of the petals on this plant was highly vari- 

 able. Its fruits were slender and contained but little seed. 

 Abut 100 seeds germinated, but gave rise solely to ro- 

 settes of O. Lamarckiana. 



To sum up: the hereditary coefficient for O. elliptica 

 was in three cases, 1 per 500 in one case, and about 

 15 % in the remaining one. The first three plants had 

 only a few hundred offspring between them, and this fact 

 in itself may be sufficient to account for the non-appear- 

 ance of cllipticas amongst them. If this is really the case 

 the last two mutants (with 0.2-15 %) may provisionally 

 be regarded as representing the normal. 



