OENOTHERA LAMARCKIANA MUT. VELUTINA. 165 



The seeds of the mutant of 1908 were sown in 1912 and gave a 

 culture of 67 flowering plants, all of which repeated the type of 

 their parent. Besides these, I sowed part of the seed somewhat later 

 in the season (June), and obtained a large group of rosettes of radical 

 leaves, of which, however, only one survived our long, wet winter. 

 This specimen flowered in 1913 on the main spike and on a number 

 of branches, was very vigorous, but not strikingly stouter than 

 the annuals of that summer. 



In 1912 I saved the seeds of 4 self-fertilized plants separately. 

 Two of them had been green from their first youth and the two 

 others had been of a pale color in the beginning. The result was, 

 in 1913, a small but distinct advantage of the two first sowings over 

 the two latter sowings. I have chosen the first ones for the crosses 

 to be described later on, and repeated this third generation in 1914, 

 in order to give the plants more space and a better manured soil, 

 and to compare such vigorous individuals with others growing in 

 a dry and poor soil. The results of this comparison have been described 

 elsewhere; they showed that the seeds produced by the two groups 

 were different. Almost all the seeds of the strong plants contained 

 a healthy germ, but among the seeds of the weaker individuals 

 there were about 25 per cent of empty ones. The germination showed 

 even a larger difference, giving about 80—90 per cent of seedlings 

 for the normal seeds and only about 50 per cent for those of the 

 weaker plants 1 ). I shall return to this phenomenon in the second 

 part of this article. 



The fifth generation was derived, in 1915, from seeds of 4 self- 

 fertilized individuals of 1914, chosen as the best ones among the 

 stronger of the groups. Sixty plants from one parent were planted 

 in my experimental garden on good soil and with plenty of space, 

 in order to be used for crosses. The remainder embraced about 

 3000 plants (between 600 and 800 from each parent) and were set 

 out in another garden in order that the degree of mutability of 

 this race might be studied. It was found to be rather small, although 

 almost all of these plants have flowered and have been carefully 

 tried at different stages of their evolution, from their germination 

 to the time when their last flowers faded away in August and their 

 first fruits ripened. 



The result of these repeated inspections has been that 4 mutants, 



*) Ueber kiinstliche Beschleunigung der Wasseraufnahme in Samen durch 

 Druck. Biol. Centralbl. 35 : 175. 1915. Opera VII, p. 56. In this article O. blandina 

 has been provisionally designated as 0. Lamarckiana mut. nov. B. 



