Tricotylous Races Do Not Arise by Selection. 411 



But when the values of several parents do not differ 

 so greatly from one another that the differences fall out- 

 side the limits of prohable error, individuals should be 

 planted out every year from all of the best parents. This 

 would, however, necessitate an increase of the cultures on 

 too large a scale. Nevertheless I extended my culture 

 as far as possible in the summer of 1898 on this principle, 

 and saved the seeds of 300 plants separately. 



The result of the 300 counts which were made on 

 these lots of seeds, embracing 300 seedlings for each 

 lot, corresponded with my expectations to this extent 

 that one of the grandparents proved to be by far the best. 

 Its hereditary value was 14%, that of its offspring had 

 a mean of 20%, and for two individuals even 25 to 27%. 

 Moreover, outside the limits of this group, this race also 

 showed an increase in hereditary capacity. 



The harvest of 1898 contained the seeds of 300 tri- 

 cotylous plants, which in their turn had been raised from 

 15 parents with values from 10 to 15%. The results 

 were as follows (expressed in percentages) : 



Parents 10 10 10 10 10 10 11 11 12 12 13 13 U 15 15 



^rr . \ Mean . 8 10 10 11 14 19 10 15 11 16 10 13 20 14 14 

 (JiTsprine^ - 



^ ^ ( Max. . 8 11 20 20 27 26 19 25 20 24 21 21 27 21 22 

 Number of offspring 1 2 19 28 11 6 8 9 27 6 36 32 12 64 39 



The mean of the whole series of counts was 12% and 

 denoted a considerable increase in the character of the 

 race. 



Let us now compare this series of figures with that 

 given on page 405 for Amarantus speciostis. That series 

 relates to the hereditary coefficients of 140, this to those 

 of 300 plants, which in the former case belong to the 

 8th, and in this one to the 9th generation. Both series, 

 therefore are the result of a selection which extended 



