No. 5S5] SHORTER ARTICLES AND DISCUSSION 57< 



The data of Table I are given graphic-ally in Pig. 1, together 

 with the curve for brother X sister and parent X offspring. 



From the table and figure it is seen that with continued in- 

 breeding according to any one of these four types the coefficient 

 approaches the value 100. The rate of approach is different, 

 however, in the different cases. The curves fall into two pairs. 

 The brother X sister and the double cousin curves are precisely 

 alike so far as concerns their curvature or shape at any given 

 point. Similarly, the parent \' offspring and single cousin curves 

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

 the cousin curves lay a y< in ral'mn behind the others. 



Let us now consider the question of the degree of inbreeding 

 following continued matings of the avuncular type of relation- 

 ship. Pedigree Table III gives a pedigree in which each mating 

 is of uncle X niece. 



PEDIGREE TABLE III (HYPOTHETICAL) 

 To Illustrate the Mating of "Uncle x Niece 











i: 



i; 











c 



i 



i; 

 (i 



{: 

 {i 

 {': 











4 



c 



c 



{; 

 {i 



X 











c 



ii 



{i 

 \: 







b 









£ 

 r. 



W 

 {? 









f 



J I- 

 1 f* 









2 







