1. The spontaneous agglutination of streptococci has been studied.
2. This spontaneous agglutination would seem to be caused by the presence of a bacterial cohesive force higher than that usually found when bacteria are suspended in salt solutions of the concentration commonly employed as electrolyte in specific agglutination reactions.
3. Many granular autoagglutinating strains of streptococcus may be made diffuse by growth at room temperature (17–23°C.) and then lose their tendency to agglutinate spontaneously.
4. All factors that reduce cohesive force or that make the repelling force relatively greater than the cohesive force make for stable suspensions.
5. Methods for management of the specific agglutination of refractory autoagglutinating strains of streptococci have been presented.