1. The sheep red cells sensitized with bacterial polysaccharide are dissolved by spcific antipolysaccharideserum and complement. 2. In this hemolytic test, the amount of the red cells run parallel to the amount of complement. 3. At first sensitized red cells are mixed with the antiserum, thereafter complement is added to this mixture, so the hemolytic test is inhibited because the red cells are already agglutinated by the antiserum.