ALLEGED MICROBIC ORIGIN OF TUMORS. 259 



been shown to be so deceptive, that the microbic origin of malignant 

 tumors has not only not been established, but rendered improbable. 

 The analogy between tumors and infective processes is more appa- 

 rent than real, and simply consists in the fact that the cells of the 

 former endowed with all the properties of independent growth 

 select the same routes for local and general dissemination as the 

 microbes of the latter. 



