CONTENTS xi 



PAGE 



the importance of electrolytes. Nature of agglutinogen. Alterations 

 by heat. Alterations in agglutinability. Seasons for agglutinability. 

 Specificity. Biological relations between bacteria parallel to agglu- 

 tinins. Castellani's method of absorption. Normal agglutinins. 

 Agglutinoids. Inhibition zones. Bordet's views. "Two phase" 

 theory. Physical interpretation. The work of Neisser and Friedemann. 

 Acid agglutination. Iso-agglutinins. 



CHAPTER X. THE PHENOMENA OF PRECIPITATION 248 



Discovery. Bacterial filtrates. Expansion of principle to proteins in 

 general. Nature of precipitinogen. Specificity. Quantitative rela- 

 tions in the reaction. Practical uses. Nuttall's studies on precipitins 

 and historical relationship. Forensic uses of the test. Performance 

 of the test as advised by Uhlenhuth. Influence of heat upon precipi- 

 tinogen. Organ specificity. Ehrlich's view of the nature of the reac- 

 tion. Physical views of the reaction. Presence of precipitinogen and 

 precipitin in same serum. Analogy with colloids of known constitution. 



CHAPTER XI. PHAGOCYTOSIS. CHEMOTAXIS. ...... 272 



Early investigations. Metchnikoff 's first studies. Phagocyto- 

 sis in lower animals. Its significance. Importance in the de- 

 velopment from the larva to the adult. Its importance in resorption of 

 degenerated cells. Varieties of phagocytosis. Giant cells. Leucocytosis 

 in response to the presence of bacteria. In the peritoneum. Phagocy- 

 tosis in tuberculosis. CHEMOTAXIS. Botanical studies. Early studies 

 of Leber. Early studies of Buchner. Methods. Theories of chemo- 

 taxis. Importance of surface tension. 



CHAPTER XII. PHAGOCYTOSIS, Continued. THE EELATION OF PHAGOCYTOSIS 



TO IMMUNITY 296 



Opsonins and tropins. Metchnikoff 's attempt to establish parallelism 

 between phagocytosis and resistance. Work of his pupils. Metchni- 

 koff 's interpretations. Origin of bactericidal substances from leuco- 

 cytes. ' ' Macrocytase ' ' and microcytase. Metchnikoff 's interpretation 

 of the Pfeiffer phenomenon. Origin of alexin. Leucocytic bacteri- 

 cidal substances. Their nature. Leucocytic ferments. Leuco-protease. 

 Petterson's experiments. Leucocytic extract of Hiss. 



CHAPTER XIII. PHAGOCYTOSIS, Continued. FACTORS DETERMINING PHAGO- 

 CYTOSIS 311 



Opsonins. Tropins. Metchnikoff 's conception of stimulins. Work of 

 Denys and his pupils. Other early observations. Work of Wright. 

 Conception of opsonins definitely advanced. Analysis of opsonic 

 action. Normal and immune opsonins. Neuf eld's opinions. Bac- 

 teriotropins. Structure of opsonins. Specific absorption of op- 

 sonins. Heat stability of immune opsonins. Eelation to other anti- 

 bodies. Eelation to alexin. Variations in leucocytes as a factor in 

 opsonic measurements. Kesistance to opsonic action on the part of 

 bacteria. Eelation to virulence. 



CHAPTER XIV. PHAGOCYTOSIS, Continued. OPSONIC INDEX AND VACCINE 



THERAPY 328 



Wright 's work on typhoid immunization. Development of technique for 

 measuring phagocytic activity. The phagocytic index. Opsonic index. 

 Dilution method. Simon and Lamar's method. Accuracy of opsonic 

 index. Wright's work on the staphylococcus infections. Eelation of 

 opsonic index to clinical conditions. Negative phase. Summation of 

 negative phase. Summation of positive phase. Clinical value of op- 

 sonic index estimations. Opsonins and tuberculosis. Treatment by 

 auto-inoculation. The value of opsonic index determinations. The 



