176 SUPPURATION AND ALLIED CONDITIONS. 



appearance of the growth in bouillon being correspondingly altered 

 (p. 170). Further, Widal and Besan^on found that a streptococcus 

 cultivated from the mouth and which was non-pathogenic, became 

 pathogenic when inoculated along with the bacillus coli communis, and 

 thereafter its virulence could be enormously increased by passing it 

 through a series of animals. These latter observers also found that 

 streptococci cultivated from the mouth of a smallpox patient were non- 

 virulent, whilst those cultivated from the blood of the same patient post 

 mortem were highly virulent, the probability being that those in the 

 blood had been derived from those in the throat. There does not 

 therefore seem at present sufficient evidence for looking upon these two 

 varieties as distinct species. It is sufficient to bear in rnind that strepto- 

 cocci in the normal mouth are usually non-virulent, and grow in short 

 chains. On the other hand, in some cases of very virulent strepto- 

 coccus infection in the human subject we have found the organism 

 occurring only in very short chains. The streptococcus conglomeratus , 

 so called from the appearance of the growth ,in bouillon, is ,to be 

 regarded merely as another variety, which forms very long chains and 

 is usually possessed of a high degree of virulence, though its distinctive 

 characters are not permanent. It has often been obtained from the 

 fauces in scarlet fever. 



We may accordingly conclude that, though it cannot be 

 definitely stated that all the streptococci concerned in the 

 production of disease in the human subject are of the same 

 species, we have not the means of classifying them as 

 distinct species. 



Bacillus coli communis. The virulence of this organism 

 also varies much and can be increased by passage from 

 animal to animal. Injection into the serous cavities of 

 rabbits produces a fibrinous inflammation which becomes 

 purulent if the animal lives sufficiently long. If, however, 

 the virulence of the organism be of a high order, death 

 takes place before suppuration is established, and there is 

 a septicaemic condition, the organisms occurring in large 

 numbers in the blood. Intravenous injection of a few 

 drops of a virulent bouillon culture usually produces a 

 rapid septicaemia with scattered haemorrhages in various 

 organs. 



Other Effects. It has been found by independent observers that in 

 cases where rabbits recover after intravenous injection of bacillus coli 

 communis, a certain proportion suffer from paralysis and sometimes 



