6 



BOTANICAL GAZETTE 



[JANUARY 



myself. In 1914 I observed for the first time a specimen of deserens 

 among these cultures, and this in a third generation. Thereupon 

 I sowed in 19 16 the self-fertilized seeds of 11 specimens in order to 

 decide whether all of them would repeat the splitting and to deter- 

 mine roughly the percentage of the new type. The results are 

 given on page 5. From these figures we see that all the speci- 

 mens tried show the same splitting, and that this is always amass 

 mutation. 



The countings for this table were partly made in the stadium 

 of the young rosettes and partly at the time of flowering. In order 

 to prove the correctness of this process, I repeated the sowings in 

 19 1 7 for those of the parents of which sufficient seed had been 

 preserved, planted out all of their seedlings, and counted them in 

 August, when they were ripening their first fruits. The results 

 are as follows: 



Although the cultures were but small, they show that the devia- 

 tions from the theoretically expected result (25 per cent) do not 

 depend upon the method of counting as used in 19 16. 



In this race I self-fertiHzed the first mutant deserens observed 

 in 19 14 and derived from it a second and a third generation in 19 15 

 and 19 16. The second generation consisted of 95 plants, of which 

 50 flowered ; the third was derived from two parents and embraced 

 77 and 140 specimens, among which 60 and 60 were left to flower. 

 All of these cultures were wholly uniform at the time of planting 

 out as well as during the flowering period. No rubrinervis and no 

 new mutants occurred among them. Thus 0. deserens is seen to 

 constitute a pure and uniform race. 



The percentage of empty grains among the seeds has been given 

 elsewhere for this race of O. rubrinervis.^ The determination was 

 made in the harvest of 5 plants of the third generation grown in 



^ Zeitschr. f. Ind. Abst. 16:262. 1916. 



