Preliminary linkage data on a long inversion in chromosome 2, involving most of the chromosome, indicates that there is a map distance from v4 to the end of the inversion about equal to the map distance from B to v4. The "left" end of the inversion lies between lg and B about 25 units from lg and 7 from B. Cytological observations show both ends beyond the inversion to be of about equal length. That would suggest that nearly half of the linkage map for chromosome 2 should lie to the right of v4. In agreement with this, about half of the known interchanges involving chromosome 2 lie beyond v4.