LIST OF ILLUSTRATIONS 



FIGURE PAGE 



Phenomenon of local skin reacti\ity to bacterial filtrates 



(Color) F)())iti.sj)iece 



1, 2. Apjjearance of skin reaction five hours after intravenous 

 injection of B. typJiosus filtrate, at skin sites previoush in- 

 jected with same filtrate 3, 4 



3. Section of skin showing microscopic appearance of hemor- 



rhagic reaction five hours after intravenous injection of 

 B. typhosus filtrate 5 



4. Section of skin showing microscopic appearance of reaction 



produced by repeated skin injections of B. typhosus filtrate 6 



5. I, Section of hypogastric lymph node six hours after in- 



travenous injection filtrate from culture of B. typhosus fol- 

 lowing preparatory injection of same filtrate into afferent 

 lymphatic. 2, Section ot arteriole in hypogastric node, show- 

 ing swelling and hyaline degeneration of wall and necrosis 

 of endothelial cells, j. Sections of pectoral nodes lollo\\-ing 

 intravenotis injection of filtrate from culture of B. typhosus 

 twent)-four hoius after jjreparator) injection of same fil- 

 trate into skin of abdomen. _/, Section of vein of common 

 iliac node which received intra\enous injection of filtrate 

 from culture of B. typhosus twenty-four hours after prepar- 

 atory injection of filtrate into the skin of medial surface of 

 thigh. 5, Section of regional inguinal lymph node removed 

 twenty-four hours after intradermal injection of filtrate of 

 culture of B. typhosus into abdomen 17 



6. Skin of back of rabbit following intradermal injections of 



meningococcus active principles and, twenty-four hours 

 later, intravenous injection of same principles 18 



7. Phenomenon of local skin reactivity to meningococcus fil- 



trate in rabbit ear 20 



8. Section from ear following same treatment as in Figure 7 21 



9. Section from area 3 cm. away from site of reaction 21 



10. Neutralization of meningococcus active principles by anti- 



meningococcus neutralizing serum 99 



XXV 



