300 



Reduplication in Gametic Series 



suppose AB to separate from ah, we caunot then represent the formation 

 of Ah and aB. Therefore we are almost compelled to suppose that 

 the original zygotic cell forms two similar halves, each AuBh, and that 

 the next division passes differently through each of these two halves, 

 in the one half separating AB from ah, and in the other half separating 

 Ah from aB. The formation of these four quadrants must take place 



AB X ab 



I AB ab j 



Ab . aB 

 I Ab.aB I 



3AB 



lAb 



Iba 



Sab 



3Ab 



IBa 



lAB 



Fig. 4. 



3aB 



in every case in which there is segregation in respect of two pairs 

 of factors. (For three pairs there must similarly be eight segments, 

 and so on.) The aa-es of this system may well be determined by the 

 position of the constituent parental gametes. Reduplication or pro- 

 liferation resulting in n - 1 gametes may then take place in either of 

 the opposite pairs of quadrants according to the parental composition. 



