+----------+-----------------+-----------------+-----------------+ | | w^c v | w^c f_a | w^c | | | ------- | --+---- | ----+- | | | f_a | v | f_a v | |Reference.+----------+------+------+----------+------+----------+ | |Eosin |Facet.|Eosin |Vermilion.|Eosin.|Facet | | |vermilion.| |facet.| | |vermilion.| | | | | | | | | +----------+----------+------+------+----------+------+----------+ | 512 | 43 | 43 | .. | 1 | 13 | 16 ~ | 513 | 28 | 35 | .. | 2 | 19 | 5 ~ | 514 | 18 | 31 | 1 | .. | 17 | 11 | | 515 | 18 | 60 | .. | .. | 20 | 15 | | 516 | 10 | 31 | .. | .. | 7 | 12 | | 517 | 24 | 34 | .. | .. | 10 | 12 | | 518 | 44 | 38 | 1 | 1 | 23 | 22 | +----------+----------+------+------+----------+------+----------+ | Total.| 185 | 272 | 2 | 4 | 109 | 93 | +----------+----------+------+------+----------+------+----------+ +----------------+------+----------------------------+ | w^c f_a v | | | | --+---+-- | | Cross-over values. | | | | | +----------+-----+Total.+------+----------+----------+ |Eosin |Wild-| |Eosin |Facet |Eosin | |facet |type.| |facet.|vermilion.|vermilion.| |vermilion.| | | | | | +----------+-----+------+------+----------+----------+ ~ .. | .. | 116 | .... | .... | .... | ~ .. | .. | 89 | .... | .... | .... | | .. | .. | 78 | .... | .... | .... | | .. | .. | 113 | .... | .... | .... | | .. | .. | 60 | .... | .... | .... | | .. | .. | 80 | .... | .... | .... | | .. | 1 | 130 | .... | .... | .... | +----------+-----+------+------+----------+----------+ | .. | 1 | 666 | 1.05 | 30.5 | 31.3 | +----------+-----+------+------+----------+----------+ {78} LETHAL SC. The third of the lethals which Miss Stark found (Stark, 1915) while she was testing the relative frequency of occurrence of lethals in fresh and inbred wild stocks arose in April 1914 in stock caught in 1910. Females heterozygous for this lethal, lethal _sc_, were mated to white males and the daughters were back-crossed to white males. Half of the daughters gave lethal sex-ratio, and these gave 1,405 cross-overs in a total of 3,053 males, from which the amount of crossing-over between white and lethal _sc_ has been calculated as 46 per cent.