580 Journal of Agricultural Research voi. xxiii, No. 7 
them to one female lacking them. The occurrence of the female lacking 
rudimentaries appears inexplicable upon the sex-linked basis, and to 
that extent the original sex-limited interpretation appears more nearly 
correct. This is especially true because the only published evidence 
against it has been the purely negative evidence of failure to find a boar 
homozygous for the factor for rudimentary mammae. The sex-linked 
interpretation is therefore abandoned. 
However, the data disclosed in the present experiments do not com¬ 
pletely support the sex-limited interpretation, although clearly indi¬ 
cating that the character is in some way involved with sex. The 
authors are somewhat at a loss to know how to regard these data. The 
aberrant individuals indicated in Table XII were recorded by three 
separate persons, none of whom was the senior author, who had had the 
greatest experience in recognition of the character. The fact of his ab¬ 
sence in the military service made it impossible for him to check the 
records, hence they are presented for what they are worth in the belief 
that their publication is less open to criticism than their suppression. 
With the exception of one female recorded as possessing rudimentaries 
which is discussed later, it will be noted that the aberrant animals possibly 
result from errors of omission rather than of commission, hence it is 
probable they represent a lack of uniformity in observation among the 
different people connected with recording the data of the study. The 
data as recorded from the different types of matings are given in Table 
XII. 
TabIvE XII .—Distribution of rudimentaries in the offspring 
Character of parents. 
Number 
of 
matings 
included. 
Number 
of 
litters 
included. 
Males. 
Females. 
With. 
Without. 
With. 
Without. 
Both with rudimentaries. 
9 
16 
56 
21 
33 
37 
Both without rudimentaries.. 
A 
c 
12 
22 
Male with, female without.... 
I 
0 
4 
8 
11 
1 
10 
Male without, female with.... 
I 
2 
1 
4 
i(?) 
11 
The numbers in bold-faced type are those which were unexpected 
according to the original sex-limited interpretation of the inheritance of 
this character. The female with rudimentaries produced in the fourth 
type of mating is quite certainly wrongly classified, for the record shows 
her to have only one rudimentary and a mammary pattern so irregular 
that it is probable the one described as a rudimentary is really the last 
mamma of the abdominal series. 
Omitting the questionable female from consideration, the following 
discussion is offered of the results in Table XII. Except for one litter 
in the first type of mating, all litters in the first and third types were 
sired by the same male, the F x Berkshire-Duroc-Jersey boar, and the 
dam of the one mating of the third type and the dams of seven of 
the nine matings of the first type were all full sisters to each other and 
to the boar. In spite of this close relationship, these matings when 
considered individually do not show a normal range of distribution in 
the ratios of males with rudimentaries to males without. Instead, four 
of the nine matings in the first type show approximate equality of males 
