122 



GENETICS AND EUGENICS 



TABLE 11a 



A Combination of Tables 10 and 11, in which the Sizk of each ' 

 F2 Class is expressed as a Percentage of the F2 Population. 

 It is assumed that the Gametic Series is the same in both Sexes 



In using Table 11a to test a case of suspected linkage, the size in per cent 

 of each observed F2 class should first be determined and comparison made 

 with the corresponding class in the Table. In cases of doubt, determina- 

 tion of the probable error of linkage may show whether the observed de- 

 partures from the normal 9:3:3:1 ratio are or are not significant. The 

 9:3:4 ratio as affected by linkage may be obtained by combining in Tables 

 10 or 11, the numbers in the columns headed aB and ab. 



