THE LIMITS OF HEREDITY 



i8 



X composite give no arches; (3) arch x loop, whorl 

 X loop, composite x loop, and loop X loop can give 

 all four types ; (4) composite is rare, but it may be 

 that composite x composite cannot give arches ; 

 (5) arch X whorl can give all types. These results 

 suggest that loop is '* much more heterozygous " than 

 arch or whorl. If composite is combined with loop, 

 simpler ratios are obtained. But the Mendelian 



Fig. 33, — ^TwiNs having the same Height, Weight, Tastes, 



Disposition, and Talents. 



They have worked together for twenty-five years and have never 



been separated. 



interpretation is unsatisfactory (i) because it is 

 unjustifiable to combine composite with loops; (2) be- 

 cause the categories are really not sharp, but a great 

 variety of transitional forms occurs; and (3) there is 

 good reason to believe that inheritance is not neces- 

 sarily from one finger of the parent to the same finger 

 of the child. The coefficient of inheritance method 

 of treatment gives low values of inheritance. 



