538 Major W, J. Tulloch. Serological Types of B. tetani in 



experiments suggested, on the contrary, that monotypical anti-toxic sera 

 may, under certain circumstances, exhibit anti-infective properties in relation 

 to the Types, The evidence of such relationship is so far only suggestive, 

 and the statement is made with reserve. 



{b) Experiments were then undertaken to determine whether any improve- 

 ment in prophylaxis might be looked for from the employment of anti- 

 bacterial sera. This investigation is still proceeding, but the following points 

 appear to be deBnitely settled from the work already completed. 



(1) Anti-bacterial sera, the anti-toxin content of which is negligible or nil, 

 ■do not prevent infection. 



(2) Evidence is so far lacking that anti-bacterial sera afford more adequate 

 protection against infection than do pure anti-toxic sera of the same given 

 anti-toxin content. 



(3) The work done suggests that monotypical anti-bacterial sera may 

 exhibit specific anti-infective properties in relation to Type. The results 

 also suggest that this specificity is more marked in the case of anti-bacterial 

 sera than in the case of anti-toxic sera. The results are, however, equivocal, 

 and this question must remain undecided until anti-bacterial sera are avail- 

 able in larger quantities than is possible when laboratory animals are used 

 for serum production. 



(4) Experiments in vitro showed definitely that specific anti-bacterial 

 immune bodies, other than agglutinins, could be produced by the inoculation 

 of whole cultures of B. tetani. For technical reasons the anti-body studied was 

 the " opsonin." The following facts were noted : — 



(a) The opsonic activity of anti-toxic sera in the presence of whole culture 

 is but slight. 



(b) The opsonic activity of sera prepared by inoculation of washed ctdtures 

 is slight, though the agglutinin titre may be high. 



(c) The opsonic activity of sera prepared by the inoculation of vjhole culture 

 is marked, and, furthermore, it is specific ; but group relationship between 

 the Types was noted in making these opsonic tests.* 



{d) From the opsonic tests, it appeared that unfiltered cultures of B. tetani 

 contain at least 3 antigens : — 



(1) Spasm-producing toxin, which is filtrable, relatively stable, and non- 

 specific. 



(2) Bacillary stibstance, which is definitely specific to the Type, and 

 stimulates production of agglutinins. 



(3) An anti-phagocytic substance {lleuaotoxia), relatively specific to each 

 Type. This antigen is either unstable or not filtrable. 



* The technique used in carrying out these tests was the dilution method of Neufeld. 



