RELATION OF PATHOGENIC TO SEPTIC BACTERIA. 11 



with reason to Pasteur^s dogmatic way of dealing with patho- 

 logical facts, such as his arbitrary definitions and descriptions 

 of what constitutes anthrax and what constitutes malignant 

 oedema. 



But while allowing all this, and perhaps even more, I think 

 all must extremely regret the tone in which Koch's criticism 

 is made ; all must think that his criticism would have been 

 much more valuable had it kept within strict bounds of an 

 objective statement. Koch shows by means of most valuable 

 observations, some of earlier date, published in his previous 

 writings (Cohn's ' Beitrage zur Biologie d. Pflanzen,' 2 Heft), 

 some of recent date, that no spore formation is possible in 

 Bacillus anthracis at a temperature below 15° C. or 59° 

 Fahrenheit. At a depth of 1 meter the temperature of the 

 soil in middle Europe is so low that the formation of spores in 

 Bacillus anthracis is practically impossible in an animal 

 buried iinopened at that depth. Koch also proves (1. c, p. 

 20) by very instructive and direct experiments with earth- 

 worms and spores of Bacillus anthracis mixed with earth, 

 that Pasteur's earth-worm theory cannot be correct. 



Various considerations of the distribution of anthrax in 

 Germany and of the manner of the outbreaks of its epidemics 

 lead Koch to the assumption (p, 29, et passim) that the 

 natural habitat of the Bacillus anthracis is really in the 

 soil, and that its casual introduction into the body of an 

 animal and the production of anthrax in it, is only " a casual 

 excursion of a micro-organism not generally limited to such 

 a parasitism." 



As mentioned just now, there is a great deal of evidence 

 for such an assumption, especially the way in which in Ger- 

 many the disease makes its appearance in animals grazing in 

 fields and meadows which occasionally become flooded. In 

 these instances it is assumed that the Bacillus anthracis 

 growing in vegetable infusions (that it does readily do so in 

 some of them is shown by Koch) of a distant locality or in 

 the depth, is carried by means of water to the surface, and is 

 left here when the water is receding or drying up, to find 



