98 



University of California PubHcations in Agricultural Sciences [\'ol. 4 



In the cultures of 1910 and 1911P, all the 1908 progeny of WG9- 

 ClO were tested. On account of the variable nature of the quanti- 

 tative character involved, an elaborate study was necessary. Only 

 small cultures could be grown in the greenhouse ; these were supple- 

 mented by larger lots in the field in 1911, but inhibition of flowering 

 by the hot summer, together with the effects of disease and soil varia- 

 tions, made the field results erratic and necessitated special methods 

 of treatment of the evidence. 



Singles — — 

 Doubles 



50 

 ■15 

 40 

 35 



30 



a: 



<u 



-a 

 g 25 



c 



c 20 



15 



10 







_ _ _ 



—in T— — T^^ =:— = 



^^ ^^ = = 



M3 M9 C2 Co Cl Mf3 M9 M4 M2 M7 C3 C7 WG W5 WIO M5 MS 



I 



I 



I 



I 



I 



I 



I 



I 



I 



I 



I 



Cl 



I 



CIO 



I 



C5 



I 



CIO 



CO 



CIO 



I 



C9 



I 



I 

 wng 



Ancestry 



Chart 1. Cultures of ]9]0. Internodes: parental values and progeny means 

 (respectively shown by dots and lines) for progeny lots 1 to 17, omitting 

 aberrant progeny. Parental values should be compared only for the same house. 



Table 7 gives the available data for the parents of the 1910 cultures, 

 and the numbers of progeny available for quantitative data. The 

 order of the pedigree numbers here is the same as that of the progeny 

 lots on the greenhouse bench. For convenience, the 1910 tests of other 

 mutant types, together with tests of several Snowflake parents, are 

 included in the table (lots 18 to 30). 



