572 
Journal of Agricultural Research 
Vol. XXIII, No. 7 
Table VII .—The relative frequency of reds, sandies , and wAfte* in the F 2 generation 
Color. 
Blacks. 
Expected 
blacks. 
Non¬ 
blacks. 
Expected 
nonblacks. 
Red. 
67 
T 7 
20 8 3? s 
20. 8x25 
13 - 875 
2.3x25 
Sandy. 
20 
14 
White. 
x / 
27 - 75 
3 
The results for the nonblacks are as good as could be desired for a 
9 to 6 to i ratio, and at once suggest that where black is absent the color 
is determined by two dominant factors, each of which produce by itself 
a sandy color and which together produce red, while the absence of 
both results in white. The results for the black-carrying pigs are a 
moderately close approximation to a 9 to 3 to 4 ratio. They suggest that 
there is one factor for sandy and a separately inherited factor which 
intensifies sandy to red, as indicated in the discussion of Table V. 
In order to reconcile the two viewpoints indicated, it is possible that 
the same conditions apply among blacks and nonblacks, except that 
there is also a dilution factor linked to black which can inhibit one 
of the factors causing sandy pigment, in the absence of the other, thus 
producing white. The factorial representation dependent on this 
suggestion follows: 
5 !=first factor producing sandy pigment. jj—its absence. 
5 2 =second factor producing sandy pigment. j 2 =its absence. 
D =dilution factor linked to black inhibiting S 2 . d =its absence. 
B =factor causing black pigment. b =its absence. 
On this hypothesis the factorial representation of the zygotes of the 
two breeds would be as follows: 
Berkshire =BD BD s x s 1 s 2 s 2 . 
Duroc-Jersey=~ TT S x S x S 2 S 2 * 
Fj —BD bd Si Si S 2 s 2 • 
The F 2 generation carrying black would then be: 
Blacks and reds 
1 2R s i s * s 2- 
2 BD BD Si Si S 2 s 2 , 
2 BD BD Si Si S 2 S 2 . 
4 BD BD Si Si S 2 s 2 . 
2 BD bdS 1 Si S 2 S 2 . 
4 BD bd Si Si S 2 S 2 . 
4 BD T 3 Si Si S 2 S 2 . 
8 BD bd Si s t S 2 s 2 . 
Blacks and sandies..J 1 s2 
[2 BD BD Si Si s 2 s 2 
f 1 Sl Sl ^2 s 2 
Blacks and whites.j 2 BD BD j, t, S, j, 
U BD BD Si Si s 2 s 2 
The F 2 generation lacking black would then be: 
2 BD bd Si Si s 2 s t 
4 BD^bd Si Si s 2 Sf 
2 BD bd Si Si S 2 S t 
4 BD bd s t Si S 2 s 2 
2 BD bd s x s^s 2 s 2 
Reds, 
Sandies. 
Whites. 
1 bd bd Si Si S 2 S 2 
2 bd bd Si Si S 2 s 2 
2 bd bd Si Si S 2 S 2 
4 bd bd Si Si S 2 s 2 
1 bd bd Si Si s 2 s 2 
2 bd bd S x s x s 2 s 2 
1 bd bd s 1 s t S 2 S 2 
2 bd bd Si Si S 2 s 2 
1 bd bd Si Si s 2 s 2 
