120 
Y. TANAKA. 
three form« of offspring in the proportion 2 : 1 : 1 as in the preceding 
generation, and the other two forms, normal white and plain yellow, should 
remain true to their parents, because they are homozygous both for the 
marking and colour characters. This assumption proved correct as may be 
seen from what is described below. 
The three classes of offspring just mentioned being mated inter se gave the 
following result in 1912. 
The plain yellow and normal white bred true to their own type, four 
matings of the former having produced 1116 individuals which were all plain 
yellow, while three matings of the latter produced 998 worms whicli were 
all normal white without excepetion. The normal yellows, on the contrary, 
splitted into three forms as in the preceding generation. 
Lot No. 
Normal 
Normal 
Plain 
Total 
yellow 
white 
yellow 
N. 4.' 'll 
168 
77 
81 
326 
N. 4.- ’ll 
154 
72 
62 
288 
N. 4. 3 ’ll 
136 
86 
68 
290 
Total 
458 
235 
211 
904 
Expectation 
452 
226 
226 
904 
express the above i 
"esult diagramatically as follows : 
1910 
Normal vellow 
X Normal yellow 
(NynY) 
| (NynY) 
Gametes 
Ny, nY 
Ny, nY 
1911 238 
1 
Normal yellow 71 
1 
Normal white 127 Plain 
Gametes 
Ny ; nY 
Ny nY 
1912 458 Normal 235 Normal 2 1 1 Plain Constant Constant 
yellow white yellow 
b) Japanese normal white ( Aojiku ) females were mated with Chinese 
striped yellow males in 1910. Two matings from this cross gave in 1911 
