GAMETIC COUPLING AND REPULSION IN THE SILKWORM. 
141 
A) Femaleness and B) black-eye 
Canary 
factor. 
a) Maleness and b ) pink-eye charac- 
complete 
Durham and 
Marryat, 
1908 
ter. 
A) Femaleness and B) masking or 
Fowl 
suppressing factor. 
a) Maleness and b) absence of mask- 
complete 
Bateson and 
Punnett. 
1908 
ing factor. 
A) Femaleness and B) barring factor. 
Spillman. 
T9Ö8 
Fowl 
complete 
Pearl and 
Surface. 
1910 
a) Maleness and non-barred character. 
Morgan and 
Goodale. 
1911 
A) Femaleness and B) dominant 
‘silver’. 
a) Maleness and b) absence of domi- 
Hagedoom. 
1909 
Fowl 
complete 
Bateson and 
1911 
nant 1 silver’. 
Punnett. 
As the above list shows, there have been observed a great many cases of 
coupling and repulsion in plants. Several cases of complete repulsion and a 
few of complete coupling 15 in animals are also known. 
But all of these interesting phenomena in animals were found in connection 
with the sex-character. There is no case of coupling or repulsion known 
to occur independently of that factor. Furthermore the phenomena of the 
partial coupling and partial repulsion have been found hitherto only in the 
vegetable world. 
According to Bateson, a coupling or a repulsion results from an unequal 
occurrence of the various gametic forms in the gametogenesis of a hetero- 
zygote, as has been mentioned at the beginning of this paper. The coupling and 
1) Bateson conceives the complete ‘coupling’ as a perfect union of the characters 
which are known to depend on separate allelomorphs. I also use the term in the same meaning. 
