OENOTHERA LAMARCKIANA MUT. VELUTINA. 181 



contain healthy and well developed germs and germinate easily. 

 This new quality is dominant over that of the parent. It is the 

 same as in almost all the older species of the genus. 



6. Moreover, 0. mut. velutina is distinguished from 0. Lamarck- 

 iana at least in one other dominant character, the smoothness of 

 its leaves at the time of flowering. Secondly, it is distinguished in 

 quite a number of characters, which seem to be more or less in- 

 dependent of one another, namely, slender stature, long internodes 

 of the flower spike, narrow and longitudinally folded leaves and 

 bracts, and cup-shaped flowers. Besides these, the richness in red 

 color and the hairiness of all organs, especially in their youth, are 

 very striking marks. 



7. In crosses with those species which split 0. Lamarckiana and 

 some of its other derivatives into the twin hybrids laeta and velutina, 

 the 0. mut. velutina produces only hybrids of the velutina type. 



8. In crosses with 0. Lamarckiana and 0. nanella, these forms 

 are seen to be split by 0. mut. velutina into twin hybrids, which 

 correspond to the twins produced by other species with them, 

 but which, of course, lack the characters of those other parents. 

 The twins of 0. blandina may be considered as pure laeta and pure 

 velutina, therefore, the former having smooth leaves and bracts 

 in the summer, the latter being identical with 0. blandina itself. 



9. The study of our new mutant reveals the existence of at least 

 two recessive characters in 0. Lamarckiana, namely, the bubbles 

 of the leaf blade and the presence of typical empty seeds. 



EXPLANATION OF PLATE I 

 At the right, Oenothera Lamarckiana mut. velutina (0. blandina); 

 at the left, 0. blandina mut. spiralis. 



(The botanical Gazette, 1917, Vol. LXIII, p. 1). 



