496 



The JoiKXAL of Hhredity 



I have arranfjcd tables for the phratries of six, five, four, three and two children, 

 in the same way. 



PHRATRIES OF SIX CHILDREN. 



4 all)inos. 

 3 albinos. 

 2 albinos. 

 1 albino. . 



5 



19 

 20 

 26 



PHRATRIES OF FIVE CHILDREN. 



5 albinos. 

 4 albinos. 

 3 albinos. 

 2 alJ)inos. 

 1 albino. . 



2.83 



1.41 



16.88 



33.77 



45.45 



PHRATRIES OF FOUR CHILDREN. 



PHRATRIES OF THREE CHILDREN. 



3 albinos. 

 2 alliinos. 

 1 albino. . 



If these tables are studied it will be 

 seen that the disc cpancy between the 

 observed and theoretical figures is not 

 noteworthy except in cases where this 

 flifTerence can l)e ex])lained In' the re- 

 mark I made that the figures of Pear- 

 son, Nettleshij) and Usher are not the 

 result of a complete census, but of a 

 cf)llcction of iniVjJished cases, where the 

 rarest instances figure in proportion- 

 ately too large a number, and where 

 on the contrarv manv common in- 



stances, such as that of a single albino 

 in a family, do not figure. It \vill be 

 noted that the discre]:)ancics observed 

 are always in the direction which this 

 remark requires, and they are imj^or- 

 lant only in the cases where their im- 

 l)c:)rtancc is ex])lained by the circum- 

 stances under which the observation 

 was made. That proves, then, the 

 exactness of my explanation. On the 

 whole, and taking account of these 

 explrmations, we may say that obscr- 



