The data from the males show that the locus of club is about midway between yellow and vermilion. This conclusion is based on the {70} evidence that yellow and club give 18 per cent of crossing-over, club and vermilion 20 per cent, and yellow and vermilion 35 per cent. The double cross-overs on this view are yellow club (3) and vermilion (3). The females furnish additional data for the linkage of club and vermilion. The value calculated from the female classes alone is 20 units, which is the same value as that given by the males. TABLE 51.--_P_1 club_ [female] [female] x _vermilion_ [male] [male]. _F_1 wild-type_ [female] x _F_1 club_ [male]. +----------+--------+-----------------+-----------------+-------+-------+ | | | Non-cross-over | Cross-over | | | | | | [male] [male]. | [male] [male]. | | | | | +------+----------+----------+------+ Total |Cross- | |Reference.|Females.| Club.|Vermilion.|Club |Wild- |[male] | over | | | | | |Vermilion.|type. |[male].|values.| | | | | | | | | | +----------+--------+------+----------+----------+------+-------+-------+ | 137 | 75 | 17 | 39 | 6 | 11 | 73 | 23 | | 138 | 64 | 24 | 32 | 6 | 8 | 70 | 20 | | 139 | 56 | 10 | 31 | 4 | 3 | 48 | 15 | | 140 | 74 | 13 | 39 | 3 | 5 | 60 | 13 | | 144 | 97 | 30 | 40 | 10 | 13 | 93 | 25 | | 145 | 63 | 15 | 29 | 4 | 6 | 54 | 19 | | 146 | 126 | 44 | 46 | 9 | 9 | 108 | 15 | | 106 | 92 | 33 | 34 | 6 | 10 | 83 | 19 | | 107 | 55 | 31 | 25 | 7 | 3 | 66 | 15 | | 108 | 86 | 29 | 32 | 7 | 10 | 78 | 22 | | 109 | 103 | 25 | 36 | 4 | 9 | 74 | 18 | | | 83 | 30 | 34 | 6 | 9 | 79 | 19 | | | 77 | 18 | 26 | 7 | 8 | 59 | 25 | | | 67 | 20 | 21 | 6 | 7 | 54 | 24 | | | 126 | 32 | 60 | 15 | 13 | 120 | 23 | | | 63 | 21 | 28 | 7 | 10 | 66 | 26 | | | 114 | 45 | 71 | 9 | 7 | 132 | 12 | | | 46 | 18 | 18 | 3 | 3 | 42 | 14 | | | 111 | 35 | 56 | 6 | 7 | 104 | 13 | | +--------+------+----------+----------+------+-------+-------+ | Total.| 1,578 | 490 | 697 | 125 | 151 | 1,463 | 19 | +----------+--------+------+----------+----------+------+-------+-------+