Spermagglutinins against seminal and epididymal spermatozoa and against seminal plasma were completely or almost completely absorbed, not only by seminal spermatozoa but also by spermatozoa from the ampullae and from the tail of the epididymis. The agglutinins of the antisera produced by the immunization of epididymal spermatozoa were absorbed very slightly by the fluids of the accessory genital organs. The antibodies against seminal plasma were very well absorbed by the fluids of the epididymis.
On agar plates, anti-seminal plasma antibodies formed five arcs with the seminal plasma of bulls, three arcs with fluid from the seminal vesicles, four arcs with fluid from the ampullae, two arcs with fluid from the tail of the epididymis and one arc with fluid from the head of the epididymis. Seminal spermatozoa, ampullary spermatozoa and seminal plasma, as well as the fluids from these organs, always removed all precipitating antibodies from the antisera. Epididymal spermatozoa absorbed the precipitating antibodies only partially, whereas their fluids did so completely or almost completely. The index of fructolysis of bull seminal spermatozoa was reduced in the medium of the antisera with the antibodies against seminal and epididymal spermatozoa. The decrease varied according to the antiserum used. Any of the substances from the genital tract which were used for the absorption of the antisera, returned the fructolysis processes to normal values.