Appendixes 





To distinguish the two kinds of F^ we ought to write 

 AB X ab as AB . ab ; and aB x Ab ought to be written 

 aB . Ab. We must in fact recognize that in the dividino- 

 zygotic cell, at some time before segregation is effected — 

 probably from the moment of fertihsation — a polarity is 

 estabHshed ; and that the constituents derived from the two 

 parents are not, in these cases at least, placed indifferently, 

 but are grouped according to their parental origin. 



Hence we may construct the following table : 



Gametic series 



Partial 



repulsion 



from zygote 



of form 



AbY. aB 



Partial 



coupling 



from zygote -^ 



of form 



ABy.ab 



( 



AB 

 I 

 I 

 I 

 I 

 I 

 I 

 3 



Ab aB 



{n-\) («-i) 



15 

 7 



ab 



7 



15 

 31 

 63 



V{«-i) 



31 



15 



7 



3 

 I 



I 



I 



I 



I 



I 



I 



3 



6 



(/z-i) 



Number 



of gametes 



111 series 



zn 



64 



3^ 

 16 



8 



4 



8 

 16 



32 

 64 



12S 

 2n 



Number of 

 zygotes 

 formed 



4;.'^ 

 4096 

 1024 



■2^6 



64 



16 



64 



1024 

 4096 



16384 



Nature of zygotic series 



AB 



2n-+ I 



7049 



513 

 129 



33 



9 



41 



177 



737 



3009 



12161 



Ab 



n 



n- - I 

 1023 



255 



63 



15 



3 



7 

 15 



31 



63 



127 



aB 



n 



;/- - I 

 1023 



255 



63 



15 



3 



7 



15 

 31 

 63 



12: 



4«'^ 3«^- (2;/ - i) 2;/ - I 2« - I 



;;^ 



9 

 49 



961 



3969 



- (2// - 



I) 



For details as to these phenomena see Bateson and 

 Punnett, Proc. Boy. Soc. 191 1, vol. 84 b, p. 3; de Vilmorin 

 and Bateson, ibid. ; Gregory, ibid. ; Bateson and Punnett, 

 Jour. Gen., i. 191 1, p. 293. 



The evidence has been obtained from observation of 

 various characters in Sweet Pea ; the relations of tendrilled 

 leaves to the ''Acacia" form in Pisum, and of Magenta 

 to Short-style in Primula Sinensis (Gregory). 



Now that we may regard the formation of four cells 

 of composition AB, Ab, aB, ab, as the foundation both 

 of the coupling- and of the repulsion-series the problem 

 is manifestly somewhat simplified. The time, excluding 

 gametogenesis, at which we can most readily imagine 

 four such definite quadrants to be formed is during the 

 delimitation of the embryonic tissues. It is then that the 

 plant is most clearly a single geometrical system. Moreover 

 the excess of gametes of parental composition characterising 

 the coupling- and repulsion-series must certainly mean that 

 the position of the planes of division by which the lour 

 quadrants are constituted is determined with regard to the 

 gametes taking part in fertilisation. Though the relative 



