| Total. | |||||
| 1,164 | 5 | 32 | 0 | 1,201 | |
| Per cent. | 96.9 | 0.42 | 2.7 | 0 |
The linkages involved in these data are very strong. The cross-overs between forked and bar number only 5 in a total of 1,201, which gives less than 0.5 per cent of crossing-over. There are 32 cross-overs or 2.7 per cent between bar and fused. The value for forked fused is the sum of the two other values, or 3.1 per cent.
LINKAGE OF SABLE, RUDIMENTARY, AND FORKED.
Rudimentary, forked, bar, and fused form a rather compact group at the right end of the chromosome, as do yellow, lethal 1, white, abnormal, etc., at the zero end. The following two experiments were made to determine more accurately the interval between rudimentary and the other members of this group. A sable rudimentary forked
male mated to a wild female gave wild-type sons and daughters. These inbred give the results shown in table 44.
Table 44.—P1 sable rudimentary forked ♂ × wild ♀. F1 wild-type ♀ × F1 wild-type ♂ ♂.
| Reference. | Wild- type ♀♀. |
|
|
|
| ||||
| Sable rudi- mentary forked. | Wild- type. | Sable. | Rudi- mentary forked. | Sable rudi- mentary. | Forked. | Sable forked. | Rudi- mentary. | ||
| 264 | 98 | 28 | 17 | 2 | 5 | 1 | 1 | .. | .. |
| 265 | 97 | 29 | 54 | 4 | 9 | .. | .. | .. | .. |
| 266 | 114 | 42 | 49 | 11 | 11 | .. | 2 | .. | .. |
| Total | 309 | 99 | 120 | 17 | 25 | 1 | 3 | .. | .. |
There were 265 males, of which 42 were cross-overs between sable and rudimentary and 4 between rudimentary and forked. The values found are: sable rudimentary, 16; rudimentary forked, 1.5; sable forked, 17.
LINKAGE OF RUDIMENTARY, FORKED, AND BAR.
The three gens, rudimentary, forked, and bar, form a very compact group. A rudimentary forked male was crossed to bar females and the daughters (bar) were back-crossed singly to rudimentary forked males, the results being shown in table 45.