104 Society for Experimental Biology and Medicine. 



2. Normal rabbit sera contain a varying amount of agglutinin 



for gonococcus. 



3. Strains of gonoccoci differ greatly in the titer of their agglu- 

 tination with various gonococcic immune sera. 



4. After one inoculation with a certain culture a large amount 

 of agglutinin was produced for some strains, but none for others. 

 Further inoculations caused an increase in the titer of the aggluti- 

 nation for certain strains but a drop in that of others. 



5. Absorption experiments indicate that an anti-gonococcic 

 serum may contain, in addition to the specific homologous aggluti- 

 nins, several groups of agglutinins which act on the different cultures 

 quite independently of one another. At least three groups were 

 found, whose major or specific agglutinins are not removed by 

 inter-absorptions. This indicates that as far as agglutination is 

 concerned there are specific differences between these groups. The 

 family gonococcus is, accordingly, heterogeneous rather than 

 homogenous, and in that respect resembles the dysentery, colon 

 and streptococcus families. In making a serum for therapeutic 

 purposes, this fact should be borne in mind. 



6. The passage of a culture of gonococcus through a guinea- 

 pig caused a very marked decrease in its agglutinability. 



7. With the exception of one serum, meningococcus aggluti- 

 nated only in low dilutions of the anti-gonococcic sera. 



8. Anti-gonococcic serum contains specific precipitins for 

 gonococcus. 



9. There appeared to be no relation between the precipitating 

 and the agglutinating properties of an anti-gonococcic serum for 

 a culture of gonococcus. 



10. Anti-gonococcic sera contain as a rule some precipitins for 

 meningococcus, but none for m. catarrhalis or staphylococcus. 



1 1. There is evidence, according to my experiments, of a rela- 

 tionship between gonococcus and meningococcus, but not of as 

 close a one as has been described by some investigators. 



