316 



Forms of Rediqdication 



Nos. found 



Expectation on ratio of 5 : 3 : 3 : 5 derived from 



SG 



64 



Sg 

 35 



(7:1:1 

 I2 : 1 : 1 



54 32 



sG 

 30 



32 



8g 



44 



5i 



The suggestion of the 2:1:1:2 ratio in the second case is made 

 on my own responsibility — Gregory does not assign one. The main 

 interest lies in the fact that the derivative ratio 5:3:3:5 explains 

 fairly well the facts of the case. 



The following diagram will serve to illustrate the hypothetical course 

 of the segregations and the cell-divisions in this case. 



liMSG 



^MsG 



P'msG 



7MSg 



5mSg 



i^msg 



The sign x signifies increase in the number of gametes, or gameto- 

 genic, segregating cells, and the following number the relative amount 

 of increase along the different axes. 



The primary and secondary reduplications, three in number, are 

 notable in that each represents a case of coupling. Let us therefore 

 consider the case in which the primary reduplications are of the form 

 1 : w : n : 1 for A and B and 1 : m : m : 1 for A and C. Under these 

 conditions the gametic series will be 



ABC + mABc + ?iAbC + nmkbc + nmaBC + 7?aBc + rwabC + abc, 



and the reduplication between B and C will be found (by extracting) to 

 be of the form 



BC : Be : bC : be :: 1 + nm : m-{- n : n-\- m : nm + 1. 



We thus get the result that the reduplication between B and C is 

 of the same form whether the ratios between A and B and A and C 



axe 



1 : n : n : 1 and I : m : m : 1 or n : 1 : 1 : n and m : 1 : 1 : m. 



