Key points are not available for this paper at this time.
Page 160, line 33, after cited add in part. Page 170, table 4, column A, delete p=2/3. Page 174, table 8, column A, for chromatin read chromatid. Page 176, lines 33 and 35, for 2r X read X/2r. Page 181, line 23, for non-modal read non-nodal. Page 197, line 13, after
Alexander Weinstein (Fri,) studied this question.