192 INFLAMMATORY AND SUPPURATIVE CONDITIONS. 



spondingly altered (p. 186). There does not, therefore, seem at present suffi- 

 cient evidence for looking upon these two varieties as distinct species. It is 

 sufficient to bear in mind that streptococci in the normal mouth are usually non- 

 virulent, and grow in short chains. On the other hand, in some cases of very 

 virulent streptococcus infection in the human subject we have found the organ- 

 ism 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 feuces in scarlet fever. 



We may accordingly conclude that, though it cannot be 

 definitely stated that all the streptococci concerned in the pro- 

 duction 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 pro- 

 duces 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 suppura- 

 tion is established, and there is a septicaemic condition, the 

 organisms occurring in large numbers in the blood. Intra- 

 venous 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 from atrophy of mus- 

 cles, especially of the posterior hmbs, these symptoms being due to lesions of 

 the cells in the anterior cornua of the spinal cord. Somewhat similar results 

 have been obtained by others after inoculations with staphylococci and strepto- 

 cocci, a certain proportion only of the animals showing paralytic symptoms 

 and corresponding changes in the spinal cord. The lesions are believed to 

 be due chiefly to the action of the products of the organisms on the highly 

 organised nervous elements. Much further research requires to be done 

 before the importance of these results can be properly estimated, but it is not 

 improbable that they will throw light on the causation of nervous lesions which 

 occur in the human subject, and the etiology of which at present is quite 

 obscure. Some observers, chiefly of the French school, consider that paralysis 

 associated with cystitis, in which the bacillus coli communis is often present, 

 may have such a causation, and that paralytic conditions following acute 

 infective fevers may be produced by the products of pyogenic cocci, which 

 frequently occur in these conditions. 



