A GEKETICOriiYSIOLOGICAL STUDY ON THE FORMATION ETC. 



39 



In tlio ciiso of tho cross " Diiikkuto " x " Togo " reils uuil liruwus were 

 oftou difficult to distiugiiisb jiccnratcly owiug to the fcviutness of the refl pigiueut 

 aud the rapidity iu chauge t(i tho hrownish colour. A considerable de\iatiou 

 fi'om the expectation thus aix)se, though the ol)seiTed nunibere are fairl}- close 

 to the approximation to a 9:3:4 ratio. 



Thh-ty six browns and twelve faint j-ellows were raised in the next year. 

 If a 9:3:4 ratio is accepted, we shotild expect among browns wliich include 

 reds and lirowns, two gixjups of families in the I'\ generation. One of them 

 should throw again red and brown, and the other should not throw red. The 

 ratio of two such families should bo 3 : 1. "We olitnincd : 



Among the red throwing famihes, tho tullowing famihes are expected : 



Among the famihes which tlii-ow no i-eds, the following famiUes are 

 expected : 



Type of families 



Segregation 



&• Brown constant, occurring once in every three. 



6, Browns and faint yellowish 3 : 1 ratio, occurring twice in every 



three. 



We found : 



