400 BIOLOGY: GENERAL AND MEDICAL 



found to depend upon a combination of those factors 

 engaged in the defense of the body. That is, there is a 

 trace of antitoxic power in the blood in those cases in 

 which toxic substances were embraced in the antigen; 

 amboceptors are present when the antigen contains the 

 essential microbes of the affection, but, above all, in all 

 cases of active immunity against infection the phagocytic 

 power of the leucocytes is greatly increased so that the 

 cells, originally inactive or feebly active, become very 

 active and hungry for the microorganisms which they 

 greedily devour and destroy. 



REFERENCES, 



R. KRAUS and C. LEVADITI: "Handbuch der Technik und 



Methodik der Immunitatsforschung," Jena, 1909. 

 ELIE METCHNIKOFF: "L'Immunite dans les maladies infec- 



tieuses," Paris, 1901. 



LUDWIG ASCHOFF: "Ehrlichs Seitenkettentheorie," Jena, 1905. 

 JOSEPH MCFARLAND: "The Pathogenic Bacteria and Protozoa" 



(8th edition), Phila, 1915. Chapters upon Infection and 



Immunitv. 

 JOSEPH MCFARLAND: Chapter upon "Immuno-Therapy," 



"Modern Clinical Medicine," volume on "Infectious 



Diseases," N. Y., 1910. 

 H. T. RICKETTS: "Infection, Immunity, and Serum Therapy," 



Chicago, 1906. 

 VALLERIE-RADOT: " The Life of Pasteur." 



