GAMETIC COUPLING 577 



As we have seen, the first example is closer f<> an 8: I 

 ratio. The second example is apparently based on an 

 experiment comprising 47 individuals ((Jregory, 1911, 

 p. 12). The classes were 33:3:1:10, and Hie author 

 states, 



The reason for this assurance is not apparent since the 

 grouping is really nearer to that resulting from a 15:1 

 ratio. The probable error, .015, is so large, however, 

 that it would be impossible to determine the grade of 

 coupling closer than to say that it probably falls some- 

 where between 8 : 1 and 31 : 1. 



The third example referred to the 15 : 1 ratio appears 

 to he based on SS5 individual- showing an association of 

 .993 ±.0017, indicating a coupling of about 20:1, the 

 deviation from the 15:1 association being 2.!) times the 



This is certainly a close approximation to the figures 

 that would result from a gametic coupling of 63:1:1: 63, 

 which for this number of individuals would be 333.27: 

 3.48 : 3.48 : 108.77. Yet the observed numbers can be still 

 more closely approximated by assuming that the coup- 



