327 



Table I. 



Reference No. 



Normal 

 fertile 



Normal 

 sterile 



Cretin 

 fertile 



Cretin 

 sterile 



No. 5 



1909 



Ol 





OD 



1 



„ 72 



V 



9ß 



1 A 



14: 





1 



„ 73 



73 



91 



1 9 



1 9 



1 



„ 74 









Ö 

 o 





75 









A 



9 



„ 70 





30 



12 



FS 



1 



X 



„ 77 





73 



43 



32 



3 



» 78 





59 



15 



24 





„ 79 





25 



12 



15 



2 





Total 



336 



150 



143 



11 



E 



xpectation 



330 



150 



150 



10 



Table IL 







Gametic series 



No. of 

 gametes 

 in series 



No. of 



zygotes 

 formed 



Nature of zygotic series 









AB 



Ab 



aB ab 



AB 



Ab 



aB 



ab 







o o 





1 



(n-1) 



(n-1) 



1 



2n 



4n2 



(2n 2 +l) 



(n-1) 



(nS-1) 



1 







— !+H 

 ~ =M CQ 





1 



31 



31 



1 



64 



4096 



2049 



1023 



1023 



1 







S| x. 





1 



15 



15 



l 



32 



1024 



513 



255 



255 



1 











1 



7 



7 



1 



16 



256 



129 



63 



63 



1 











1 



3 



3 



1 



8 



64 



33 



15 



15 



1 









1 



1 



1 



1 



4 



16 



9 



3 



3 



1 







from 

 B x ab 





3 



1 



1 



3 



8 



64 



41 



7 



7 



9 









7 



1 



1 



7 



16 



256 



177 



15 



15 



49 











15 



1 



1 



15 



32 



1024 



737 



31 



31 



225 







%■ 



© ^ 





31 



1 



1 



31 



64 



4096 



3009 



63 



63 



961 







tial 



te o: 





63 



1 



1 



63 



128 



16384 



12161 



127 



127 



3969 







M O 



Pi >> 





(n-1) 



1 



1 



(2-1) 



2n 



4n2 



3n 8 -(2n-l) 



(2n-l) 



(2n-l) 



n 2 -(2n-l) 





These records (Table I) shew that the appearance of a small 

 proportion of sterile cretins is a constant feature in those families 

 and we suggest that their presence may be accounted for as 

 follows. The repulsiou between N and F is to be regarded as 

 partial, and of such a nature that the series of gametes produced 

 by the Fi plant is NF : 3 Nf : 3 nF : nf. 



Such a series of ovules fertilised by a similar series of 

 pollen grains would give rise to a generation consisting of 

 33 normal fertiles, 15 normal steriles, 15 cretin fertiles, and 



