A GENETICO-PHYSIOLOGIC AL STUDY ON THE FORMATION ETC. 
47 
white grains segregated by the ratio 9:3:4 in the descendants of certain 
natural hybrids, and the red grain plants were purple-pigmented whereas the 
grey-brown plants were unpigmented. A similar case was found in the cross 
between two Japanese varieties, “ Otsubu ” x “Haguro The grain of the 
former was pale buff (“ white ”) and the latter was reddish brown. In the 
F 2 plants the following result was obtained. 
Table 20. 
« 
Showing the result obtained in F . z , 
“ Otsubu ” x “ Haguro ” 
Colour of 
reddish 
brown 
Colour of grains 
yellow 
brown 
pale buff 
(white) 
Total 
Awn Paleas 
Purple Self purple 
119 
— 
36 
155 
Purple Loc. purple 
33 
— 
12 
45 
Brown Brown 
— 
33 
11 
44 
„ Yellow 
— 
12 
4 
16 
152 
45 
63 
260 
Expect. (9:3:4) 
146.25 
48.75 
65.00 
Diff. (ob. —exp.) 
+ 5.75 
-3.75 
-2.00 
Probable errors 
±5.375 
±4.485 
±4.007 
The yellowish brown grains were not found in the purple awn plants. 
The ratios of coloured to white grains in each awn type showed a normal 
3 :1 ratio (see Table 20), so it is certain that a linkage relation exists between 
the genes for the purple awn and for the reddish brown grain. With respect 
to the colour of the awn, purple and brown showed a 3 : 1 ratio, and in the 
palea, self purple, localized purple, brown and yellow segregated by the ratio 
9 : 3 : 3 : 1 (155 : 45 : 44 :16 observed against 146.25 : 48.75 : 48.75 :16.25 ex¬ 
pected) as in the case with the cross “ Hanbunnento ” x “ Genroku-moclii ”, 
already reported in the section (c). These two crosses differ with respect to 
the colour of paleas, only from the gene groups which enter from the parental 
plants, but the manner of segregation in the F, generation is the same, thus : 
