Abstract
Summary Schultz-Dale tests with ilea from guinea pigs infected with 100, 500, 1000 or 2100 Toxocara eggs for 4, 6 or 10 weeks indicated increased sensitization with increased numbers of worms and duration of infection. Schultz-Dale tests detected variable, but striking, quantitative differences between stage-specific antigens and heterologous antigens of Toxocara, Ascaris, and Trichinella. Desensitization tests pointed towards means of identifying antigens in other parasites that are common to Toxocara. Tests for passive cutaneous anaphylaxis correlated with Schultz-Dale tests, but hemagglutination and gel diffusion tests did not.