CHAPTER XIV

IMMUNITY ACQUIRED BY NATURAL MEANS 433 Immunity acquired after recovery from infective diseases.—Immunity acquired in malaria.—Humoral properties of convalescents from typhoid fever.—Preventive power of the blood of persons who have recovered from Asiatic cholera.—Antitoxic power of the blood of persons who have recovered from diphtheria. Immunity acquired by heredity.—Absence of hereditary immunity properly so called.—Immunity conferred by the maternal blood and by the yolk. Immunity conferred by the milk of the mother.