THE PROBLEM OF INBREEDING 125 



ILLUSTRATION IV. UNCLE X NIECE MATING 



Let US now consider the question of the degree 



of inbreeding following continued matings of the 



avuncular type of relationship. Pedigree Table 



V gives a pedigree in which each mating is of uncle 



X niece. 



From this table it appears that the values of the 

 coefficients of inbreeding will be exactly the same 

 for this type of mating as in the case of single 

 cousin mating. Or, in other words, Z's form the 

 following series. 



Values of Coefficients of Inbreeding for Continued 



Uncle X Niece Mating 



From the data presented it is clear that in- 

 breeding continued for about ten generations, 

 quite regardless of the type of mating provided 

 only it be continuously followed, leads to within 

 one or two per cent of complete *' concentration of 



