Contents xv 



PAGE 



against toxins is not in direct ratio to the amount of antitoxins in the 

 body fluids. — Hyperseusitiveness of an animal treated with toxin. — 

 Diminution of the susceptibility of the organism immunised against toxins. 

 Hypotheses as to the nature and origin of antitoxins. — Hypothesis of the 

 transformation of toxins into antitoxins. — Hypothesis of receptors 

 detached from cells as the source of antitoxins. — Hypothesis of the 

 nervous origin of tetanus antitoxin. — Fixation of tetanus toxin by the 

 substance of the nerve centres. — The relations between saponin and 

 cholesterin. — Anti-arsenic serum. — Part played by phagocytes in the 

 struggle of the animal against poisons. — Probable part played by phago- 

 cytes in the production of antitoxins. 



CHAPTER XIII 



Immunity of the skin and mucous membranes ..*... 403 



Protective function of the skin. — Exfoliation of the epidermis as a means of 

 ridding the animal of micro-organisms. — Localisation and arrest of micro- 

 organisms in the dermis. — Intervention of phagocytes in the defence of 

 the skin. 



Elimination of micro-organisms by the conjunctiva. — Microbicidal function of 

 the tears. — Absorption of toxins by the conjunctiva. — Protection of the 

 cornea. — Elimination of micro-organisms by the nasal mucosa. — Protection 

 by the respiratory channels. — Dust cells. — ^Absorption of poisons by the 

 respiratory channels. 



Alleged microbicidal property of the saliva. — Part played by microbial pro- 

 ducts in the protection of the buccal cavity. — Antitoxic function of the 

 saliva. 



Antiseptic action of the gastric juice. — Antitoxic function of pepsin. 



Protective function of the alimentary canal. — Absence of microbicidal power 

 from the intestinal ferments. — Protective function of the bile. — Antitoxic 

 r61e of the digestive ferments. — Favouring and retarding functions of 

 the intestinal micro-organisms. — Destruction of toxins by these micro- 

 organisms. 



Defensive role of the liver. Protective function of the lymphoid organs of the 

 alimentary canal. 



Protective function of the mucous membrane of the genital organs. — Auto- 

 purification of the vagina. 



CHAPTER XIY 



Immunity acquired by natural means 433 



Immunity acquired after recovery from infective diseases. — Immunity ac- 

 quired 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. 



