Contents xv 



PAGE 



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

 body fluids. Hypersensitiveness 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 dennis. 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 

 role 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 XIV 

 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. 



