Report on the Bacteriology of Water. 



317 



of organic materials ; but in no case does it support the view that 

 Bacillus anthracis can live and multiply like a water bacterium in 

 ordinary waters (p. 273). 



20. As regards the behaviour of that variety of anthrax bacillus which 

 is known as " asporogene" and which is incapable of forming spores 

 under any known circumstances whatever, our experiments are not 

 yet sufficiently advanced to warrant any conclusions being drawn from 

 them at present (pp. 274 — 278). The great manipulative difficulties 

 of experiments with spore-free bacilli have already been pointed out, 

 and no one has, so far as we know, as yet, overcome them. 



In conclusion, we would point out that the chief hygienic interest 

 of our investigation is centred in the behaviour of the anthrax spores, 

 which, as we have already pointed out, may be regarded as repre- 

 sentative of the extreme limit of endurance possessed by patho- 

 genic bacteria ; on the other hand, the most important question to be 

 examined was whether the bacilli of anthrax can grow and multiply 

 or form spores in such waters, and our results point to this being- 

 possible only under special conditions. We trust, therefore, that the 

 information which we have collected, both from our own experi- 

 ments and from the published results of other observers, concerning 

 the behaviour of these hardy anthrax spores, may serve as a basis for 

 practically assessing the higher limit of possible vitality which may 

 be exhibited by pathogenic micro-organisms gaining access to potable 

 water. 



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