Tricotyloiis Half Races. 385 



12 were hemi-tricotyls and one was a tetracotylous speci- 

 men. There were also some few syncotylous ones. The 

 ratio from the best seed-parents was no more than from 

 0.8% to 1.1%. The tricotylous offspring of these and 

 of some with from 0.5 to 0.6% were planted out in the 

 same way as in the previous year, provided they were 

 strong little plants. This time the inflorescence of each 

 plant was guarded against the visits of insects by means 

 of a parchment bag and artificially fertilized in the hope 

 of thus isolating individuals producing higher propor- 

 tions. 



On page 354 I have plotted, in Fig. 66, a curve of the 

 harvest of 1894, based on the records made in the spring 

 of 1895. There were two seed-parents wdiich manifested 

 an advance on the previous year, inasmuch as their ratio 

 was 3.5% and Z.7%, but the difference was only a 

 very inconsiderable one. In all, there were 87 seed- 

 parents. As I had planted the offspring ot the individual 

 grandparents of 1893 together in groups in 1894, I 

 could now make a selection not only betw^een the parents 

 but also between the grandparents. The grandchildren 

 of those grandparents only, whose offspring had pro- 

 duced the highest mean proportion, were planted out. 

 By means of such a selection of grandparents the pedi- 

 gree becomes an individual one in spite of the size of the 

 mltures, embracing, in each generation the offspring of 

 one selected individual only. The method, therefore, 

 unites this principle with the greater certainty that can 

 be obtained by extensive cultures and a double selection. 

 I have also applied it to a number of other cases. 



From one grandparent with 1%, therefore, and from 

 six of its offspring with from 0.9% to 2.1% 54 tricotvl- 

 ous specimens in all were planted out ( 1895). From the 



