2. From a comparison of pachytene figures in different inbred lines it is apparent that consistently "good" figures may be obtained from some lines and consistently "bad" figures from others. Hybrids of good and bad lines have bad figures and plants with good figures are recovered in backcrosses to lines with good figures with a frequency suggesting that a single major recessive gene for good pachytene figures is involved.

Lines having consistently good pachytenes include Luces Favorite (parent of 29-3 hybrid), 4-8d, L 289, CC5, OS426. Lines with badly clumped pachytenes of poor quality include B 164, OS 420, WF 9, 38-11 and 040B.

The observations on the quality of the pachytene figures were made under a wide variety of climatic conditions in New York and southern California, involving appreciable differences in temperature, humidity, and time of day when fixations were made. The quality of the cytological preparations was remarkably uniform under a wide diversity of environmental conditions.

L. F. Randolph