CO 



THE BOTANICAL MAGAZINE. 



LVol. XXXVI. No 42S. 



is not due to a chance fluctuation, but to the interference to which 

 he gives especially the name of "Negative interference. " 



I consider that the interference which occurred in my experiment 

 is to be classified as " Negative interference." I have found that in 

 my case the coincidence is 1.46. 



Comparing the few examples of the coincidence which were obtained 

 by other investigators with mine, it will be tabulated as follows. 







Double crossing-overs 



Sum of the 



Coincid- 







Observed 



Expected 



two regions 



Drosophila 

 melanog aster 



vermilion 



sable 0.28 



bar 



1.28 



23.58 



0.21 Morgan 1 ) 



Drosophila 

 melanogaster 



purple 



black 1.07 

 curved 



0.97 



23.46 



1.11 



Bridges 



Drosophila 

 . simvlans 



yellow 



rubyoid 



tiny-bristle 



5.08 



6.27 57.5 



0.81 



Sturte- 

 vant 2 > 



Drosophila 



simvlans 



rubyoid 



forked 



tiny-bristle 



0.31 



0.24 



41.2 



1.27 



») 



Primula 



sinensis 



red stigma 

 long style 

 red flower 



2.9 



4.1 



47.8 



0.71 



Altenburg 



Pharbitis Nil 



variegated 



rolled 8.9 



heart-shaped | 



6.08 



58.1 1.46 



Hagiwara 



In concluding, I must express my hearty thanks to Prof. Takashi 

 Sasaki who has given me valuable helps during my experiments, 

 and also to Dr. Kiichi Miyake and Mr. Yoshitaka Imai who were 

 very helpful in writing this paper. 



agricultural college, 



Imperial University of Tokyo. 



1) Sex-linked inheritance in Drosophila, Carnegie Pub. No. 737, 1916 



2) Genetics, Vol. VI. 1921. 



