AN ANALYSIS OF THE EFFECT OF SELECTION. 

 Table 14. — 868, Inbred Minus Line. 



17 



CROSSBRED MINUS SERIES. 



The following cultures furnished the material for this series: 



Cultures 920, 1063, 1073, 1082 of the 900 minus line. 



Cultures 935, 936, 1047 of the 868 minus line. 



Culture 942, made up by mating together two 4-bristled Dichjets 

 from 912, which in turn was the result of mating a sepia, spineless, 

 kidney, sooty, rough male to a female from a daughter culture of 

 869 (see pedigree of 900 line). 



Culture 949, made up by mating a female of the constitution — - — ; — - 



P Ss6 To 



(from the cultures of Mr. J. W. Gowen) to a male from culture 916 

 (see pedigree of 1002 line). 



All the cultures in this series traced to 868, and the ''generation" 

 given is the greatest number of generations from 868, which is thus 

 the standard for this line, just as 864 was for the crossbred plus series. 



Table 15 and figure 8 give the results for the series. Here again, 

 the effectiveness of selection is suggested, but is doubtful. The means, 

 however, are lower than in any other series except the 868 line, and 

 that line entered very largely into the make-up of this one. 



Speck Minus or 1331 Line. 



In connection with certain experiments to be described below it 

 became desirable to have a minus line that should be recessive for some 

 second chromosome character. Accordingly culture 1331 was made 

 up by mating a 4 female from 1168, Fe of the crossbred minus series, 

 to a speck male.^ The line was then inbred, in pairs, brother to sister, 

 minus selected, and gradually made homozygous for speck, sepia, and 

 rough. 



