1. The p-amino and p-nitromonobenzyl ethers of the specific polysaccharide of Type III Pneumococcus have been prepared.
2. The diazonium ether of the specific polysaccharide has been coupled with serum globulin to yield a specific polysaccharide-protein complex and this complex has been used for immunization. The results of the immunological studies are presented in the following paper.