20 VACCINE AND SEKUM THEKAPY 



serum of an animal immune to the disease, as that of 

 the hen, forms a good culture medium for the bacillus. 

 The explanation of the phenomenon of the first 

 example I shall deal with later, or, to be more precise, 

 a possible explanation. The explanation of the later 

 example is probably as follows : It has been shown 

 by Browning, Zinsser, and Johnson, that the sera of 

 animals, on standing, form an anti-complementary 

 body, which destroys the function of the complement. 

 Now, in the case of the hen's serum, in vivo it has 

 a complete immunity to anthrax bacilli, but in vitro, 

 on standing, it forms anti-complement, thereby losing 

 its immune powers and so becoming a suitable culture 

 medium for the bacilli. 



Anti-complement and Anti-amboceptors. — There 

 are many agencies which seem to interfere with a 

 hemolytic or bacteriolytic system of any antigen- 

 antibody-alexin complex. The^ so-called anti-com- 

 plementary substances are many, among those of 

 most interest being lipoids and globulins of the 

 serum. Noguchi has demonstrated a lipoidal sub- 

 stance in many normal sera which directly inhibits 

 the action of complement and is thermostable. 

 Hemolytic sera, having the powder of destroying red 

 blood cells, must necessarily prove, in the presence of 

 sufficient complement, to be a powerful poison when 

 introduced into animals whose corpuscles they are 

 able to injure. By careful and gradual dosage with 

 such hemolytic sera, Ehrlich, Morgenroth, and 

 Bordet have been able to produce immunity against 



