1913 |Stark. | |Bar |Eye-shape | 12-13 | B' | 57.0 | Feb. 1913 |Tice. | |Notch |Wing | | N' | 2.6 | Mar. 1913 |Dexter. | |Depressed* |Wing | G | d_p | 18.0 | April 1913 |Bridges. | |Lethal sb |Life | | l_sb | 16.7 | April 1913 |Stark. | |Club* |Wings | H | c_l | 14.6 | May 1913 |Morgan. | |Green* |Body-color| | | | May 1913 |Bridges. | |Chrome* |Body-color| | | | Sept. 1913 |Bridges. | |Lethal 3 |Life | | l_3 | 26.5 | Dec. 1913 |Morgan. | |Lethal 3_a_ |Life | | l_3a | 19.5 | Jan. 1914 |Morgan. | |Lethal 1_b_*|Life | | l_1b | 1.1- | Feb. 1914 |Morgan. | |Facet* |Eye | | f_a | 2.2 | Feb. 1914 |Bridges. | |Lethal _sc_ |Life | | l_sc | 66.2 | April 1914 |Stark. | |Lethal _sd_ |Life | | l_sd | | May 1914 |Stark. | |Furrowed |Eye | | f_w | 38.0 | Nov. 1914 |Duncan. | +------------+----------+-------+-------+--------+------------+---------+ The factors are located preferably by short distances (_i.e._, by those cases in which the amount of crossing-over is small), because when the amount of crossing-over is large a correction must be made for double crossing-over, and the correction can be best found through breaking up the long distances into short ones, by using intermediate points. Conversely, when a long distance is indicated on the chromosome diagram, the actual cross-over value found by experiment (_i.e._, the percentage of cross-overs) will be less than the diagram indicates, because the diagram has been corrected for double crossing-over. {22}