Abstract
Agglutination tests utilizing rabbit sera have shown possible antigenic differences between 2 types of trichomonads from the hog. These strains were isolated from the nose and cecum respectively of the same hog which was affected with atrophic rhinitis. These 2 trichomonad types proved to be antigenically as different from each other as each was different from Trichomonas foetus, a trichomonad from cattle.