+------------+-------+------------+-----------+-----+----+ | | | B | C | | | | | +-----+------+-----+-----+ | | | Reference. | A | D | E | F | G | H | I | +------------+-------+-----+------+-----+-----+-----+----+ | 52 | 96 | 25 | 30 | 16 | 11 | 82 | 33 | | 52' | 176 | 59 | 64 | 24 | 19 | 166 | 26 | | 53 | 60 | 20 | 22 | 9 | 6 | 57 | 26 | | 53' | 76 | 21 | 27 | 11 | 10 | 69 | 31 | | 54 | 88 | 35 | 38 | 14 | 16 | 103 | 29 | | 54' | 60 | 22 | 20 | 8 | 9 | 59 | 29 | | 57 | 61 | 22 | 20 | 7 | 11 | 60 | 30 | | 57' | 170 | 47 | 54 | 24 | 19 | 144 | 30 | | 58 | 128 | 37 | 55 | 14 | 10 | 116 | 21 | | 58' | 144 | 38 | 64 | 16 | 15 | 133 | 23 | | Firsts | 433 | 139 | 165 | 60 | 54 | 418 | 27 | | Seconds | 626 | 187 | 229 | 83 | 72 | 571 | 27 | | +-------+-----+------+-----+-----+-----+----+ | Total | 1,059 | 326 | 394 | 143 | 126 | 989 | 27 | +------------+-------+-----+------+-----+-----+-----+----+ FORKED. On November 19, 1912 there appeared in a stock of a double recessive eye-color, vermilion maroon, a few males which showed a novel form of the large bristles (macrochaetae) upon the head and thorax. In this mutation (text-fig. E) the first of several which affect the shape and distribution of the bristles, the macrochaetae, instead of {58} being long, slender, and tapered (see Plate 1, fig. I), are greatly shortened and crinkled as though scorched. The ends are forked or branched, bent sharply, or merely thickened. The bristles which are most distorted are those upon the scutellum, where they are sometimes curled together into balls. LINKAGE OF VERMILION AND FORKED. [Illustration: FIG. E.--Forked bristles.] Since forked arose in vermilion stock, the double recessive for these two sex-linked factors could be used in testing the linkage relations of the mutation. Vermilion forked males were crossed to wild females and gave wild-type males and females, which inbred gave in F_2 the results shown in table 39. Forked reappeared only in the males in the following proportion: not-forked [female], 742; not-forked [male], 346; forked [male], 301. The result shows that the character is a sex-linked recessive. TABLE 39.--_P_1 wild_ [female] [female] x _vermilion-forked_ [male] [male]. _F_1 wild-type_ [female] [female] x _F_1 wild-type_ [male] [male].