1. The hemolytic type of the Bacillus coli may be recovered from the intestinal tract of patients with chronic ulcerative colitis in a high percentage of cases. If four or more specimens from a single individual are examined, it is shown to be present in one hundred per cent of the cases. The results are similar to those obtained from a study of stool cultures from healthy individuals. 2. The hemolytic strains of the Bacillus coli recovered from proctoscopic smears were found to be somewhat more virulent for white mice than the nonhemolytic. However, the virulence of the hemolytic type was approximately the same as for those recovered from the stools of healthy persons, while the nonhemolytic showed a somewhat lower virulence. 3. The Bacillus coli recovered from the intestinal tract of patients with colitis appear to be heterologous strains having agglutinins more or less in common with each other and with those isolated from the stools of healthy people. 4. From this study it may be concluded that in incidence and biological characteristics, hemolytic and nonhemolytic strains of Bacillus coli recovered from proctoscopic smears of patients with chronic ulcerative colitis, differ in no respect from those obtained from stool specimens of healthy individuals.