45O BACTERIOLOGY. 



made in bacteriology. Even the discovery of 

 the cholera bacteria in 1884 by Koch and his 

 co-workers Gaffky and Fischer was of less 

 importance because of the fact that this in- 

 vestigation was not brought to a satisfactory 

 termination ; indeed, Lister in 1891 at the 

 International Congress in London declared 

 that the etiological significance of the comma 

 bacilli first became admissible through the 

 proof brought by Hueppe of the formation of 

 poison. (That the parasitic bacteria exert their 

 effect through the formation of poison has been 

 set forth fully in preceding sections.) Along 

 this line of work there is as yet no proof that 

 micro-parasites occur as the exciting cause of 

 the typical acute exanthemata like small-pox, 

 typhus fever, scarlet fever and measles. It is 

 certainly striking that the results up to the 

 present time should be negative in just those 

 diseases most markedly contagious, and this 

 is perhaps explicable on the supposition that 

 bacteria are not concerned in these affections. 

 Enlightenment as to the germs causing 

 malignant tumors, especially the epithelial 

 tumors and among them the carcinomas would 

 be equally desirable. The objects that have 

 up to the present been described as the para- 

 sites of carcinoma will not stand criticism. 

 Important reasons, moreover, are adduced for 



