Reference. Non-cross-overs. Cross-overs. Total. Cross-
over
value.
Miniature sable. Wild-type. Miniature. Sable.
38 I 245 283 15 17 560 6
43 I 191 236 13 18 458 7
46 I 232 274 24 21 551 8
Total 668 793 52 56 1,569 7

Since the results for the male and the female classes are expected to be the same, the sexes were not separated. The combined data give 7 per cent of crossing-over between miniature and sable.

LINKAGE OF VERMILION, SABLE, AND BAR.

Bar eye has been described by Mrs. S. C. Tice (1914). It is a dominant sex-linked character, whose locus, lying beyond vermilion and sable, is near the right end of the chromosome series, that is, at the end opposite yellow.

In the first cross of a balanced series of experiments for the gens vermilion, sable, and bar, vermilion (gray not-bar) entered from one side (♀) and (red) sable bar from the other (♂). The daughters were bar and the sons vermilion. The daughters were back-crossed singly to the triple recessive males vermilion sable (not-bar), and gave the data included in table 14.

In the second cross, vermilion sable (not-bar) went in from one side (♀) and (red, gray) bar from the other. The daughters were bar and the sons were vermilion sable. Since these sons have the three recessive factors, inbreeding of F1 is equivalent to a triple back-cross. The results are given by pairs in table 15.

Table 14.—P1 vermilion ♀ ♀ × sable bar ♂ ♂. B. C. F1 bar ♀ × vermilion sable ♂ ♂.

Reference.

Total. Cross-over values.
Ver-
milion.		 Sable
bar.		 Ver-
milion
sable
bar.		 Wild-
type.		 Ver-
milion
bar.		 Sable. Ver-
milion
sable.		 Bar. Ver-
milion
sable.		 Sable
bar.		 Ver-
milion
bar.
147 I 81 66 12 15 15 18 207 13 16 29
148 I 103 108 4 19 11 11 256 9 9 18
149 I 97 88 10 8 17 17 1 1 239 8 15 22
150 I 95 75 10 11 21 22 1 1 236 10 19 27
151 I 116 96 11 15 23 26 2 289 10 18 26
89 89 94 10 19 15 11 1 239 13 11 23
90 49 50 4 8 15 14 140 9 21 29
91 104 88 13 15 12 12 244 11 10 21
Total. 734 665 74 110 129 131 3 4 1,850 10 14 24

Table 15.—P1 vermilion sable ♀ ♀ × bar ♂ ♂. B. C. F1 bar ♀ × vermilion sable ♂ ♂.