LINKAGE OF SHIFTED, VERMILION, AND BAR. In order to determine on which side of vermilion shifted lies, a shifted vermilion (not-bar) female was crossed to a (not-shifted red) bar male. Three factors are involved, of which one, bar, is dominant. The shifted vermilion (not-bar) stock is a triple recessive, and a three-point back-cross was therefore possible. The daughters were bar and the sons were shifted vermilion (the triple recessive). Inbred these gave the results shown in table 46. The smallest classes (double cross-overs) are shifted and vermilion bar, which places shifted to the left of vermilion at approximately 17.8 units from yellow. TABLE 47.--_P_1 shifted vermilion_ [female] x _bar_ [male] [male]. _F_1 bar_ [female] x _F_1 shifted vermillion_ [male] [male]. +-------+---------------+---------------+---------------+---------------+ | | s_h v | s_h B' | s_h v B' | s_h | | Refer-| ------ | --+---- | -----+- | --+-+-- | | ence. | B' | v | | v B' | | +----------+----+--------+------+---------+-----+--------+------+ | |Shifted |Bar.|Shifted |Verm- |Shifted |Wild-|Shifted.| Verm-~ | |vermilion.| | bar. |ilion.|vermilion|type.| | ilion~ | | | | | |bar. | | | bar. | +-------+----------+----+--------+------+---------+-----+--------+------+ | 65 | 56 |108 | 15 | 20 | 8 | 33 | 1 | 1 | +-------+----------+----+--------+------+---------+-----+--------+------+ +----------+------+----------------------------+ | | | | |Reference.|Total.| Cross-over values. | | | | | | | +----------+---------+-------+ ~ | |Shifted |Vermilion|Shifted| ~ | |vermilion.|bar. |bar. | | | | | | | +----------+------+----------+---------+-------+ | 65 | 242 | 15 | 18 | 31 | +----------+------+----------+---------+-------+ The stock of shifted has been thrown away, since too great difficulty was encountered in maintaining it, because, apparently, of sterility in the females. LETHALS SA AND SB.