230 



MAINE AGRICULTURAL EXPERIMENT STATION. 



1915- 



are of the same shape. The essential point of difference is that 

 the, cousin curves lag a generation behind the others. 





















y 



[^ 















/M 















1 





/ 













/ / 



'1/ 



1 / 















// 



// 



// 



1 > 



























, 





GCMCRATIOMS 



Fig. 50. Curves of inbreeding, showing (a) the limiting case of con- 

 tinued brother X sister breeding, wherein the successive coefficients of 

 inbreeding have the maximum values; (&) continued parent X offspring 

 mating; (c) continued first-cousin X first-cousin mating where the 

 cousinship is double (C X C^)> and (d) continued first-cousin X first- 

 cousin mating where the cousinship is single (C X C). The continued 

 mating of uncle X niece gives the same curve as O X C 



Avuncular Matings. 



We may next consider the degree of inbreeding which follows 

 continued mating of the type uncle X niece. Pedigree Table III 

 gives a pedigree which is of this sort. In this, as in all the other 

 pedigrees in this paper, the upper of two bracketed individuals 

 is regarded always as the male, and the lower as the female. 

 Thus in Pedigree Table III individual & is a female, the niece 

 of individual a with whom she is mated ; her father e having 

 been a full brother of a. 



