No. 585] SHORTER ARTICLES AND DISCUSSION 571 



There are, of course, two possible sorts of first cousins, single 

 and double. In the first case one of the parents of any individual 

 is a brother (or sister) to the one of the parents of the other indi- 

 vidual in the mating. In the second case, both the parents 

 occupy this relation to the parents of the other individual in the 

 mating. 



These two sorts of first cousinship are shown in Pedigree Tables 

 I and II. 



PEDIGREE TABLE II (HYPOTHETICAL) 

 To Illustrate the Continued Breeding of First-Cousin X First-Cousin 



It will be seen that Pedigree Table I and the third column of 

 Table I are different from the corivspondinir values given on 

 pages 591 and 592 of the earlier paper. The present values 

 should be substituted for the earlier ones, which were based upon 



