<p> Transplantable methylcholanthrene induced tumor was studied in relation to tumor immunity in its syngeneic hosts, A/Jax mice, The tumor was characterized by cytogenetic, histological and electron microscopic procedures, A technique was developed to establish a state of active immunity by immunizing animals with Sendai virus fused tumor cells. The specificity of immunoprotection was determined by the resistance to the challenges with viable tumor cells and the delayed hypersensitivity test. Adoptive transfer of anti-tumor immunity and cellular response of lymphoid cells from immunized mice were followed to examine the expression of cell-mediated reactions. Circulating antibody of the immune serum was demonstrated by immunofluorescent technique and the enhancing effect on the growth of the transplanted tumor. The relationship of these results to the current knowledge of tumor immunology was discussed </p>. / Thesis / Doctor of Philosophy (PhD)