1. The reactions of several sulfated polysaccharides and glycogen to a series of histochemical tests are described. 2. The accepted significance of a positive periodic acid Schiff reaction appears to hold true in these substances. 3. Although the alcian blue staining of the sulfated polysaccharides is attributed primarily to their acidic groups, their appropriate hydroxyl groups can influence the stainability. 4. The azure A metachromasia and methylene blue staining of the sulfated polysaccharides confirm largely the validity of the hitherto established reaction mechanisms. A finding worthy of recording is that chromic acid oxidation abolishes metachromasia of some sulfated polysaccharides. 5. Throughout the present study discussions were made on the possible mechanisms involved in the reactions observed.