xvii.] SEPTIC AND PATHOGENIC ORGANISMS. 231 



I have made a series of experiments with the view to 

 obtain pure cultivations of definite septic micro-organisms : 

 various species of micrococci, bacterium termo, and 

 bacillus subtilis, of which the morphological characters 

 could with precision be ascertained and which at starting 

 were tested to be barren of any power of inducing disease. 

 I have cultivated these in pure cultivations for many 

 generations, and under varying conditions, and then I have 

 inoculated with them a large number of animals (mice, 

 rabbits, and guinea-pigs) ; and to put it briefly, I have not 

 found that hereby any of them acquired the least pathogenic 

 power. 



