Studies of the responses of basophil and eosinophil leucocytes and mast cells to the nematode Trichostrongylus colubriformis. I. Observations during the expulsion of first and second infections by guinea-pigs.

During expulsion by guniea-pigs of both first and second infections with the intestinal nematode parasite Trichostrongylus colubriformis, increased numbers of basophils and eosinophils were present in the bone marrow and blood. In addition, increased numbers of basophils, mast cells and eosinophils, many possessing reduced numbers of cytoplasmic granules, accumulated at the sites of infection. Blood eosinophil counts, however, did not show significant changes during the early part of a first infection.