406 Tricotyloiis Races. 



appear to be the very best, but to cultivate also some of 

 the next best seed-parents for the continuation of the 

 race. Of the culture of 1897 I selected five, viz., those 

 with 16, 17, 17, 21 and 25%. In order to allow as manv 

 different external factors as possible to come into play, 

 I sowed the following generation in two subsequent years 

 (1898 and 1899), and in the first year in two separate 

 lots, one in the middle of April and one in the middle of 

 May. Altogether somewhat over 400 tricotylous plants 

 were planted in this year, and the hereditary capacity was 

 determined on 300 seedlings in each lot. 



But in spite of every care, the result was a return to 

 ])revious values, and this in the case of every one of the 

 five parents. The mean value for all of them was only 

 2%; the five highest values were 9.6 — 10.6 — 10 — 11 — 

 11% mostly amongst the offspring of the same grand- 

 parent (E in the following table). Below I give a short 

 review of the values found separately for each individual 

 grandparent of 1897. The countings were made in the 

 spring of 1899. 



A. Grandparents in 1897 A 



Their values in spring 1898 . 



B. Parents sown on April 21st, 1898: 

 Their values in spring 1899: 



Maximum 



Mean 



C. Parents sown on May 7th, 1898: 

 Their values in spring 1899: 



Maximum . 9.6 6.6 4.6 6.3 7.3 



Mean 4.1 2.2 2.1 2.5 2.5 



Mean of the two series ... 2.8 1.5 1.4 1.8 3.6 



The two grandparents with 16 and 25% must there- 

 for be regarded as the best ; and it must be supposed that 

 the five exceptionally high figures were brought about 



