In this paper, there was a simple but serious error in Table 1. The two first rows of the figures in the table had changed places. The corrected table is given below (Table 1). The error does not affect the main conclusion of the paper, namely that mus309 has an effect on intergenic but not on intragenic meiotic recombination. On the other hand, after the correction the results are now in correspondence with the results of other authors, like McVey et al. (2007). The mus309 mutation has a stronger effect on crossing over frequency in the chromosome regions where the frequency of crossovers in the wild type females is lowest in relation to the physical map length of the chromosome than in the regions where crossovers respectively are most common. In the wild type flies there is a trend that crossovers become less frequent relative to the physical map length the closer the centromere, on the one hand, or the distal tip of the chromosome, on the other hand, is located.
1 In Stevens' (1936) formula for calculating the coefficient of coincidence:
where w is the number of flies which were double crossovers, x and y are the numbers of flies which were single crossovers for cv and v, and v and f, respectively, and n is the total number of flies.