| 0|3823| F1 | Do. | 0 | Do. | 8|..|..|..|..|..|..|..|..|..|..| 0.00| | 135 |804|4716| F2 | Do. | 0|3823| F1 | Do. | 0 | Do. |19|..|..|..|..|..|..|..|..|..|..| 0.00| | 136 |804|5431| F2 | Do. | 0|3823| F1 | Do. | 0 | Do. |16|..|..|..|..|..|..|..|..|..|..| 0.00| +------+---+----+-----+---------+---+----+-----+--------+---+--------+--+--+--+--+--+--+--+--+--+--+--+-----+ In table 38 I have given in the section lying between that headed "Father" and that headed "Offspring" the "Matings." This column differs from the others of the table in not being, in general, based upon observation, but upon a sometimes complicated judgment. Of course, all of the F1 generation, where this generation occurs, may be taken as of DR composition; but the decision as to whether a given individual of F2 is a DR, an extracted dominant, or an extracted recessive is not always easy, because of the manifestation of imperfect dominance. But the assignments are by no means arbitrary. Taking the Brahma crosses, which are by far the most numerous, we see, from tables 31, B and 33, that those F2 individuals that have a boot of grade 6 or higher are almost certainly extracted recessives (which are equivalent to pure-bred Dark Brahmas). Those with a grade of 3 or even 4 and lower to 2 or even 1 are probably heterozygotes, while those with grade 0 and some of those with grade 1 are extracted dominants. In cases of doubt the distribution of grades in the offspring will give the deciding vote. In case the individual has been used as a parent in more than one mating the results in all the matings are taken into account, for the germinal constitution of an individual must be regarded as fixed at all times and in all matings. The assignment under "Matings" has, then, been made by the application of the above rules. In tables 39 to 43 there are grouped together the progeny from matings of the same sort, selecting from table 38 the crosses into which the Dark Brahma enters as the booted parent. TABLE 39.--_RR × RR crosses from table 38._