The variability of crude protein, crude fiber, hexosans, pentosans, ether extract, and ash was studied in 100 alfalfa plants selected from a segregating population between intercrosses of Medicago sativa L. and M. falcata L. It was found that plant types as classified by visual judgment were unreliable indicators of chemical constituents in plants. Frequency distributions showed that variability among the 100 plants was large for all six chemical constituents in both leaves and stems. There was no significant correlation between leaves and stems for crude protein, crude fiber, ether extract, and ash, but there was a slight positive relationship for hexosans and pentosans. Crude protein and crude fiber content, while giving a correlation coefficient of −.983 in the leaves, gave only −.446 in the stems. Crude protein and hexosan content were negatively correlated in the leaves but not in the stems.