+------+---------+----------+-------+---------------------------------+ | | | Mother. | | Offspring (No. of toes). | |Serial| Pen No. +---+------+ f +---+---+---+---+---+---+---------+ | No. | |No.|No. of| |4-4|5-4|5-5|4-6|5-6|6-8| Average.| | | | | toes.| | | | | | | | | +------+---------+---+------+-------+---+---+---+---+---+---+---------+ | 1 | 734 815 |499| 6-6 |21{_a_ | 2 | 1 | 7 | 0 | 3 | 8 | 10.3 | | | | | | {_b_ | 1 | 0 | 3 | 0 | 0 |17 | 11.4 | | | | | | | | | | | | | | | 2 | 734 815 |773| 6-5 |13{_a_ |.. |.. | 6 | 0 | 3 | 4 | 10.9 | | | | | | {_b_ |.. |.. | 2 | 1 | 1 | 9 | 11.4 | | | | | | | | | | | | | | | 3 | 734 |500| 5-5 | 8{_a_ |.. | 2 | 4 | 0 | 2 |.. | 10.0 | | | | | | {_b_ |.. |.. | 3 | 2 | 2 | 1 | 10.5 | +------+---------+---+------+-------+---+---+---+---+---+---+---------+ In table 19 the series _a_ of observed average numbers of filial toes (10.3, 10.9, 10.0) and the series _b_ obtained by assigning the typical full number to all reduced types (11.4, 11.4, 10.5) are decidedly irregular. There is, however, between the parental and the filial series a correlation of +0.250±0.070. This indicates a slight tendency for the number of toes in the progeny to vary with those of the parentage. The second set of data is derived from special matings made with hybrids between Houdans and 4-toed races. On the one hand, in pens 728 and 813, cocks with well-developed toes of the duplex type were mated with hens as nearly as possible of the same sort; while in pens 765, 769, and 820 cocks with small, imperfectly separated toes (probably of the duplex type[4]) were mated with hens as far as possible of the same sort. [4] I say probably of the duplex type because the cock of pen 769 had a distally split toe on the right foot, reminding somewhat of the _reduced_ triplex type. But as the left foot had a typical duplex thumb, and the triplex is not common in Houdans, it should probably be classed as duplex. Tables 20, 21, and 22 give in detail and in summary the distribution of types of polydactylism in the families from well-developed and in those from poorly developed parents. They show a great difference between the offspring of parents with good extra-toe (table 20) and those with poor extra-toe (table 21). The former yield over 80 per cent offspring with 5 toes or more on one or both feet, while the latter yield about 57 per cent of such.