Abstract
When polygalactosamine (APS) produced by Aspergillus parasiticus was mixed with cells of Cryptococcus neoformans it produced a “capsular reaction” and agglutination similar to that caused by specific antibody. The positively charged APS molecule also caused precipitation of various negatively charged (acidic) polysaccharides including gum acacia and capsular polysaccharides of C. neoformans and pneumococcus. Dextran was not precipitated by APS.