Feb. 17, 1923 
Inheritance in Swine 
561 
was neither dominant nor recessive, but that the faces of the resulting 
Fj animals were intermediate between the two parental types. Simpson 
did not give the data for the F 2 generation, and none of the F t individuals 
in this experiment reproduced. Hence the number of factors responsible 
for the differences in face shape between these three breeds is not 
known. The data, however, indicate this much: Tamworth straight, 
long face is dominant over Berkshire short, dished face; Yorkshire dished 
face forms as intermediate F 1 with Tamworth long, straight face. 
Therefore, Yorkshire dished face and Berkshire short, dished face are 
apparently similar phenotypes produced by somewhat different factor 
complexes. 
The face shape of the Duroc-Jersey is intermediate between those of 
the breeds just discussed, in that it is moderate in length and in dish, 
while the forehead and the hair which grows upon it usually slope 
smoothly upward and backward. In the F t generation of the Berk¬ 
shire X Duroc-Jersey cross, the forehead in every case approaches 
closely that of the Berkshire type (PI. 1, D). The face was strongly 
dished, but not to the degree of the Berkshire ideal, although it ap¬ 
proached this ideal much more closely than the Duroc-Jersey type. A 
slight amount of variation was shown by two animals of the F t genera¬ 
tion, but the dish was pronounced enough to be Berkshire in type 
(PI. 1, H, I). The second of the two F x litters from which breeding ani¬ 
mals were selected was much more typically Berkshire than the first. 
Both litters were out of the same dam, but they were sired by different 
boars. In every case the length of face was considerably less than the 
Duroc-Jersey and approached the Berkshire type. Here, too, there was 
some variation. 
In the F 2 generation very much wider variation was observed. No 
practicable means of measuring any of the three elements of face shape 
was devised, but since they differed so distinctly, and there was so 
little chance of mistake, they were classified according to their resem¬ 
blance to one or the other of the parental types. The face shape does 
not develop completely until the animal is mature, hence there are 
available only the data for the 42 F 2 animals which had reached maturity 
when the experiment was discontinued. These data are summarized 
in Table II. 
TablR II .—Inheritance of facial characters in Berkshire-Duroc-Jersey cross 
Facial character. 
Similar to 
Berkshire. 
j Intenne- 
! diate. 
I 
Similar to 
Duroc- 
Jersey. 
Forehead shape... 
37 
2 
3 
Dish of face. 
T 7 
9 
16 
Length of face. 
21 
7 
14 
The widest variation was in the length of face, some being longer 
than the typical Duroc-Jersey and some shorter than the typical Berk¬ 
shire. There was some evidence of correlation between length of face 
and dish of face since hogs both with extremely dished and extremely 
long faces did not occur. On the other hand, short-faced hogs occurred 
both with extremely straight and with extremely dished faces. This 
