Dr. Holló Ferenc szerk.: Parasitologia Hungarica 4. (Budapest, 1971)
excretions" of Taenia pisiformis and Cysticercus pisiformis as antigens . Rabbits 6 to 7 weeks old, weighing 700-900 gm, were infected orally with 500 T. pisiformis eggs, and 60 days later some of them received a reinfection with 10 000 eggs. On the 100th day after the primary infection, all animals were killed and examined. Serum samples were taken at different times after the infection and were tested for the presence of precipitins to somatic and "metabolic" antigens of T. pisiformis and C. pisi formis by double diffusion method, using the combined system. Precipitating antibodies could first be detected on the 11th day after the infection, and all rabbits produced detectable amounts of precipitins from the 30th day. The dynamics of the antibody response were characterized by a gradual increase of the mean titre from the second week of infection, with a peak between days 4-0 to 70 followed by a noticeable decrease. Rabbits responsed to reinfection with an increased synthesis of precipitins. The invasion of T. pisiformis oncosphaeres induced a complex precipitin response in the rabbits: four precipitating antibodies of different specificity were detected. The precipitin activity of the serum samples from individual rabbits varied considerably. The serum from reinfected rabbits contained precipitins against wider spectrum of antigens than serum from rabbits that received only a single infection. Antigenic components reacting specifically with precipitins in the serum of infected animals were found in both whole extracts and "secretions and excretions" of T. pisiformis and C. pisi- formi s , and also seem to be contained in the acid-soluble fraction of Cysticercus extract. Saline-soluble whole extracts of T.pisiformis and C. pisiformis are antigenically complex, each consisting of at least 6 to
