416 Tricotylous Races. 



each plant are sufficient, and this is a great advantage 

 as compared with the laborious process of harvesting in 

 Scrophularia. 



My culture began in the summer of 1896. At that 

 time the prospect of obtaining an intermediate race in 

 the other two races had already become very remote. 

 From some plants in our botanical garden I saved seeds 

 which produced 13 tricotyls, 4 hemi-tricotyls and one 

 tetracotyl amongst 300 seedlings, i. e., 6%. This figure 

 was considerably higher than most of the values of my 

 half races mentioned on page 392, and about as high 

 as the value attained by Amarantiis and Scropluilaria at 

 that time. At the same time six other species of Oeno- 

 thera were tested with reference to their production of 

 tricotyls. I found from to 1 and 2% and therefore 

 selected the 0. Berteriana. In the spring of 1897, tri- 

 cotyls only were potted singly, and planted out in July 

 in the beds. Their hereditary values were determined in 

 the following year in the case of 15 plants. They fluctu- 

 ated between 1 and 12% and exhibited a mean of 4%. 

 In the following generation, 1898, I was able to plant out 

 about 60 strong tricotyls, and since that time I have con- 

 ducted the cultures on this scale wath only slight modi- 

 fications. 15 tricotyls from the plant with 12%, and 45 

 from those wnth 6 to 7% were planted out. The former 

 group, however, proved to be no better than the latter. 

 The values of these plants varied from 2 to 16%, with 

 a mean of 4%. The best of the five other groups, how- 

 ever, had values varying from 6 to 16%, with a mean 

 of 8% (from 10 separate crops). The remainder varied 

 between 4 and 11, with a mean of 6%. I selected the 

 three best parents whose values were 15, 16 and 16%, 

 and T planted out the strongest tricotylous ofifspring of 



