Two populations derived respectively from callus tissue of sugarcane clones H 37-1933 and H 50-7209 were studied for differences in morphology, chromosome number, and four enzyme systems. Variations observed in morphological characteristics were not directly correlated with differences in enzyme systems. Greater variation in both respects was observed in plants from the H 50-7209 (a chromosomal mosaic) population than in plants from the H 37-1933 (chromosomally stable) population. Among 37 plants of H 50-7209, all but one had cell-to-cell variation in chromosome number. In all but one of these 36 variable plants, the overall range was 2n = 94-120. The exceptional plant had a range of 2n = 17-118. Among 8 plants of H 37-1933, all had 2n = ca. 106.