FURTUKR DMA ON TllK KKI )i;ri.U A TK )N IN SI I .IvWORMS. 
9 
I lu)ut;h the pri'CcdiuL;' [Jcclit^^rcc bct^ins \\ itli the cross of dominant 
and rcccssi\'c whites, we nia\- put the iiihiliitor, to w liieh the luigdad white 
owes its doniinanc)-, out of consideration in the present iiu'csti^ation, 
because the descendants ^■i\en above all belong- to the \'elK)w series in 
which the factor in (juestion is necessarily absent. 
The result in 1912 is what ina}' be accounted for on the basis that 
the parents were nnYy x NnYy ^ , and i : 2 : 2 : i repulsion occurred 
in male side. On such assumption we may e.\;j)ect the follow ing- zygotic 
series, which is \'er\' close to the actual figiu'es. 
Normal 
Normal 
Plain 
Plain 
Total 
yellow 
white 
yellow 
white 
Observed 
134 
6o 
182 
32 
408 
Expected 
136 
68 
170 
34 
408 
(4) 
(5) 
(0 
The numbers 
; in the spring- 
191 3 precisely accord 
to 9 : 
3:3: 
:ries, the expectation being as 
follovN's : 
Normal 
Normal 
Plain 
Plain 
Total 
yellow 
white 
yellow 
white 
Observed 
.07 
35 
29 
10 
181 
Exjjected 
102 
34 
34 
II 
181 
The result seems suggestive to normal distribution of gametic forms 
in both sexes. Nevertheless I am inclined, from the following reasons, 
to believe existence of the underlying reduplication cv'en in this case. In 
tlic first place, some of the normal yellows in 191 2 (No. 42o'i3) were 
possibly produced by union of the gametes Ny and nY, while others were 
deriv^ed from combination of UY and ny ; thus the reduplication in the 
former -was repulsion, and that in the latter was coupling. In the second, 
the sexual dimorphism of gametic series in the reduplication hitherto 
described, must be assumed to exist also in the present case. If therefore 
it chanced a repulusion to occur in one parent, the fathci\ and a coupling 
to take place in another, the mother, the gametic series would be 
