1. The specific polysaccharide content of pneumonic lungs in Type III pneumonia was 60 times greater than in Type I, II, VII, and VIII cases.
2. The highest values were obtained from gray hepatized lobes, but the red hepatized and edematous areas also contained large quantities of S.
3. Comparable yields of polysaccharide were recovered from the sputa and lungs of fatal cases.
4. Preliminary peptic digest of lung exudates increased the S yields.
5. The data support the hypothesis that the outcome in Type III pneumonia is related to the ability of the pneumococci to produce capsular polysaccharide.