title: The ontogeny of the immune system.
mesh_terms: D000818:Animals; D000906:Antibodies; D001402:B-Lymphocytes / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D002060:Bursa of Fabricius / Q000276:immunology; D002454:Cell Differentiation; D002645:Chickens / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D005796:Genes; D006801:Humans; D007109:Immunity; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007136:Immunoglobulins / Q000096:biosynthesis; D008264:Macrophages / Q000276:immunology; D010587:Phagocytosis; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000906:Antibodies; D007136:Immunoglobulins