+----+------------------------+--------------------------+-----------------+-------+ | | Mother. | Father. | Offspring. | | | +----+-------------+-----+---+----------------+-----+-----+-----+-----+Nature | |Pen | | | No. | | | No. | | | | of | |No. | No.| Races. | of |No.| Races. | of | 4-4 |4-5 | 5-5 |mating.| | | | |toes.| | |toes.|toes.|toes.|toes.| | +----+----+-------------+-----+---+----------------+-----+-----+-----+-----+-------+ | {|2011|Polish × Min.| 4-4 |444|F2 Houd. × Legh.| 4-4 | 10 | .. | .. | R × R | | {|2614| Do. | 4-4 |444| Do. | 4-4 | 6 | .. | .. | R × R | |762{|2333| Do. | 4-4 |444| Do. | 4-4 | 16 | .. | .. | R × R | | {|2618| Do. | 4-4 |444| Do. | 4-4 | 2 | .. | .. | R × R | | {|3776| Do. | 4-4 |444| Do. | 4-4 | 2 | .. | .. | R × R | +----+----+-------------+-----+---+----------------+-----+-----+-----+-----+-------+ Two sets of data are available for answering these questions. The most direct set includes the data derived from crossing "pure-bred" polydactyl birds and the other includes the data derived from using hybrids between normal-toed and polydactyl ancestors. The latter data have the advantage that the parents offer a greater variability; but they have the disadvantage that the germinal condition of those parents is incompletely known. The pure races may be considered first. Eight matings of Houdans, each parent with 5 toes, gave 122 offspring, of which 116 had 5-5 toes, 3 had 4-5 toes, and 3 had 4-4 toes. The variability of the toes is not great in the parent Houdans. But, arranging them in the order of development of the toes, the most developed first, the series of table 18 results. TABLE 18. +------+---------+-------+--------------------------+ | | | | Offspring. | |Serial| Pen No. |No. of +-----+-----+-----+--------+ | No. | |mother.| 4-4 | 4-5 | 5-5 |Average.| | | | |toes.|toes.|toes.| | +------+---------+-------+-----+-----+-----+--------+ | 1 | 727 803 | 2457 | 1 | 2 | 34 | 9.89 | | 2 | 727 803 | 3105 | 1 | 0 | 45 | 9.95 | | 3 | 803 | 2579 | .. | 1 | 12 | 9.92 | | 4 | 727 | 3106 | .. | .. | 4 | 10.00 | | 5 | 727 | 2494 | 1 | 0 | 5 | 9.67 | | 6 | 727 | 2459 | .. | .. | 16 | 10.00 | +------+---------+-------+-----+-----+-----+--------+ No direct relation here appears between development of the extra toe in the parents and the average number of toes in the offspring. Of the Silkies, 3 hens were used in 5 matings. The same 6-toed cock (No. 774) was employed throughout (table 19). TABLE 19.