If we consider the female classes of table 11, we get information as to the cross-over value of eosin and sable, namely, 42 units. The male classes will be considered in connection with the cross that follows.
The next experiment involves the same three gens which now enter in different relations. A double recessive, eosin vermilion (gray) female
was mated to (red red) sable males and gave 202 wild-type[[5]] females and 184 eosin vermilion males. Two F1 pairs gave the results shown in table 12 (the four classes of females not being separated).
Table 12.—P1 eosin vermilion F1 wild-type ♀ × F1 eosin vermilion ♂ ♂.
| Reference. | F2 females. | F2 males. | |||||||
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| Eosin Ver- milion ♂. | Sable ♂. | Eosin sable ♂. | Ver- milion. ♂. | Eosin Ver- milion sable ♂. | Wild- type ♂. | Eosin ♂. | Ver- milion sable ♂. | ||
| 59 C | 133 | 40 | 33 | 7 | 16 | 5 | 5 | 2 | 1 |
| 61 C | 101 | 34 | 26 | 8 | 11 | 3 | 7 | 1 | 0 |
| Total | 234 | 74 | 59 | 15 | 27 | 8 | 12 | 3 | 1 |
If we combine the data for males given in table 12 with those of table 11, we get the following cross-over values. Eosin vermilion, 32; vermilion sable, 12; eosin sable, 41.
LINKAGE OF MINIATURE AND SABLE.
The miniature wing has been described (Morgan, Science, 1911) and the wing figured (Morgan, Jour. Exp. Zool., 1911). The gen for miniature lies about 3 units to the right of vermilion, so that it is still closer to sable than is vermilion. The double recessive, miniature sable, was made up, and males of this stock were bred to wild females (long gray). The wild-type daughters were back-crossed to double recessive males and gave the results (mass cultures) shown in table 13.
Table 13.—P1 wild ♀ ♀ × miniature sable ♂ ♂. B. C. F1 wild-type ♀ ♀ × miniature sable ♂ ♂.