Table 32.—Distribution of boot-grades between a high and low grade of boot in parents.

HIGH AND LOW GRADE OF BOOT IN PARENTS.
Pen No.Mother.Father.Grade of boot in offspring.
No.Gen.Races.Gra.No.Gen.Race.Gra.012345678910Aver-
age.
8515567PBl. × Bf. C.9P7526Silkie.3............2.........3358.15
8513410PDo.9P7526Do.3...............4321617.29
8516956PDo.87526PDo.3............33...22...57.13
8512073PDo.77526PDo.3...1...11...111326.91
8512299PDo.77526PDo.3............2211......36.78
851840PBf. C.107526PDo.3............1...1......1...6.33
8511002PDo.87526PDo.3.........312124116.27
815131PBk. C. 10774PDo.4.........311221126.23
851841PBf. C.107526PDo.3............1...1...1......6.00
851838PDo.87526PDo.3.........4243......225.65
Totals (116)01011141613101317216.77

So far as the average grade of boot in offspring goes, this table stands between that of the Cochins (table 31, A) and that of the Silkies (table 31, C). But what is especially striking is the apparent dimorphism revealed in the line of totals. There is one (empirical) mode at 10, corresponding with that of the Cochins, and a second clear mode at 5, corresponding to that of the Silkies. If we assume the Cochin to be homozygous in boot (RR) and the Silkie to be heterozygous in boot, then we can interpret the high mode as extracted recessives, the median mode as heterozygotes.

C. RESULTS OF HYBRIDIZATION.

We have next to consider the nature of the inheritance when one parent belongs to an unbooted race, the other to a booted one (table 33).

Table 33.—Distribution of boot-grades in the F1 generation of booted × non-booted parents.

A. COCHIN CROSSES.
Pen No.Mother.Father.Grade of boot in offspring.
No.Gen.Races.Gra.No.Gen.Races.Gra.012345678910Aver-
age.
7731334PW. Legh.0836PBl. Coch.10.........31111...2...5.44
773193PDo.0836PDo.10...1268742.........4.27
7731366PDo.0836PDo.10.........2521............4.20
773127PDo.0836PDo.10......3109124............4.11
773692PW. Legh. (R)0836PDo.10.........1032...............3.47
7742075PCoch.81431PW. Legh. (R)0611...1..................0.78
Totals (111)6263127241030203.91
B. DARK BRAHMA CROSSES.
727YPD. Br.10381PHoud.0............23212......5.80
727121PDo.10381PDo.01......1154............4.67
8232030PDo.73858PM × P0......51615412.........3.67
823YPDo.83858PDo.0......1762...............3.56
8383814PW. Legh.0122PD. Br.6...226611............3.28
838202PMin.0122PDo.6......253..................3.10
83871PW. Legh.0122PDo.6.........1.....................3.00
8383832PDo.0122PDo.611...112..................3.00
83810PDo.0122PDo.6...1...31..................2.80
816121PD. Br.94912PM × P 0......8411...............2.64
8165838PDo.94912PDo.0......551..................2.64
8385418PW. L., Min.0122PD. Br.6113311...............2.50
8165979PD. Br.64912PM × P04347411............2.46
8162353PDo.54912PDo.0...2241..................2.44
8165977PDo.44912PDo.0...321...1...............2.14
8165835PDo.54912PDo.035583..................2.12
8165840PDo.54912PDo.051341..................1.64
8236626PDo.23858PDo.011022.....................1.33
8165980PDo.54912PDo.05815.....................1.32
Totals (268) 213745834721932002.84
C. SILKIE CROSSES.
774777PSilkie.81176PW. Legh.03...111..................1.50
744681PDo.51176PDo.01121111...............0.94
744469PDo.11176PDo.0113...........................0.21
Totals (37)2552221000000.76
SUMMARY.
Crosses.Grades of boot in offspring, reduced to percentages.
012345678910Aver-
age.
Cochin.5.41.85.428.024.321.69.02.70.01.8...3.91
Brahma.7.813.816.831.017.57.83.41.10.7......2.84
Silkie.67.613.55.45.45.42.7...............0.76

An inspection of Table 33, which gives the distribution of grades of boot in the offspring constituting the first hybrid generation, might well lead to the conclusion that inheritance is here of a blending nature, or that, if either condition is dominant, it is the booted one, as suggested in my report of 1906. On this hypothesis the offspring with no boot illustrate imperfection of dominance, and one would say that, in booting, dominance is very imperfect.

However plausible such an interpretation might appear when based on the first hybrid generation alone, it becomes untenable when subsequent generations are taken into account, as we shall see later. The hypothesis breaks down completely in the second hybrid generation and we are forced to the opposite hypothesis, namely, that the clean-shanked condition is dominant. Such an hypothesis would seem, at first, to contravene the principle enunciated in my report of 1906 that the more progressive condition is dominant over the less progressive condition, or absence. But such is not necessarily the fact. We have no right to assume that presence of boot is the new character. The rest of the body of poultry (save the head) is covered with feathers. If the foot is not it must be because there is something in the skin of the foot that inhibits the development of feathers there. And this inhibiting factor is dominant over its absence.