BACTERIA IN WATER. 649 



mann), Bacillus plicatus, Bacillus deyorans (Zim merman n), Bacillus gracilis 

 (Zimmerinann), Bacillus guttatus (Zimmermann), Bacillus implexus (Zim- 

 mermann), Bacillus punctatus (Zimmermann), Bacillus radiatus aquatilis 

 (Zimmermann), Bacillus vermiculosus (Zimmermann), Bacillus cpnstrictus 

 (Zimmermann), Bacillus fluorescens aureus (Zimmermann), Bacillus fluo- 

 rescens longus (Zimmermann), Bacillus fluorescens tenuis (Zimmermann), 

 Bacillus fuscus (Zimmermann), Bacillus rubefaciens (Zimmermann), Bacil- 

 lus subflavus (Zimmermann), Bacillus janthinus (Zopf), Bacillus mycoides 

 (Fliigge), Bacillus tremelloides (Tils), Bacillus cuticularis (Tils), Bacillus 

 filiformis (Tils), Bacillus ubiquitus (Jordan), Bacillus circulans (Jordan), 

 Bacillus superficialis (Jordan), Bacillus reticularis (Jordan), Bacillus ru- 

 besceiis (Jordan), Bacillus hyalinus (Jordan), Bacillus cloacae (Jordan), 

 Bacillus delicatulus (Jordan), Bacillus violaceus laurentius (Jordan). 



PATHOGENIC BACILLI. 



Bacillus typhi abdominalis (Eberth, Gaffky), Bacillus erysipelatos suis 

 (" Bacillus murisepticus, " Koch), Bacillus septicsemiae haernorrhagicae 

 ("Bacillus cuniculicida," Koch), Proteus vulgaris (Hauser), Proteus mira- 

 bilis (Hauser), Bacillus canalis capsulatus (Mori), Bacillus canalis parvus 

 (Mori), Spirillum cholerae Asiaticae ("Comma bacillus," Koch), Bacillus coli 

 communis (Escherich), Bacillus hydrophilus fuscus (Sanarelli), Bacillus 

 venenosus (Vaughan), Bacillus yenenosus brevis (Vaughan), Bacillus vene- 

 nosus invisibilis (Vaughan), Bacillus venenosus liquefaciens (Vaughan). 



The following additional species are described by Zimmermann (1894) in 

 his second publication ("Die Bakterien unserer Trink- und Nutzwasser "). 

 Micrococcus candidus, Micrococcus coralloides, Streptococcus cinereus, Mi- 

 crococcus sulpliureus, Micrococcus galbanatus, Micrococcus erythromyxa, 

 Sarcina flavea, Sarcina aurantiaca, Sarcina rosea. Bacillus ruber, Bacillus 

 miiiiaceus, Bacillus mesentericus roseus, Bacillus carnosus, Bacillus chryso- 

 gloia, Bacillus multipediculus flavus, Bacillus villosus, Bacillus radiatus, 

 Bacill us fluorescens al bus, Bacillus viridans, Bacillus turcosa, Bacillus halans, 

 Bacillus nacreaceus, Bacillus mirabilis, Bacillus umbilicatus, Bacillus lactis 

 viscosus, Bacillus syiixanthus, Bacillus sericeus, Bacillus minutus, Bacillus 

 stellatus, Bacillus radicosus, Bacillus vemicosus, Bacillus mucosus, Bacillus 

 centralis, Bacillus spumosus, Bacillus aiinulatus, Bacillus liquefaciens, Bacil- 

 lus disciformans. 



The following spirilla and " vibrios" have also been found in water- 

 chiefly in river water : 



Spirillum volutans, Spirillum sanguineum, Spirillum serpens, Vibrio ru- 

 gula, Spirillum plicatile, Spirillum marinum (Russell). Spirillum cholerae 

 Asiaticse, Spirillum of Renon, Vibrio aquatilis (Gunther), Vibrio of Weibel, 

 Vibrios of Bujwid (Bacillus choleroides a and 6), Vibrio of Loffler, Vibrios 

 of Boiihoff, Vibrio of Blackstein, Vibrios of Sanarelli, Vibrios of Fischer, 

 Vibrio Beroliiiensis, Vibrio Danubicus, Vibrio of Pfuhl (v. Metchnikovi ?). 

 Several of the " vibrios" in this list which have recently been obtained from 

 river water in various parts of Europe are probably varieties of the cholera 

 spirillum. 



ADDITIONAL NOTES UPON BACTERIA IN WATER. 



It is now generally recognized by bacteriologists that the potability of 

 water is to be determined by an investigation relating to the presence or ab- 

 sence of known pathogenic bacteria, rather than by an estimate of the num- 

 ber of bacteria present in each cubic centimetre of the water under exami- 

 nation. From a sanitary point of view the most important of these pathogenic 

 bacteria are the cholera spirillum and allied " vibrios," the bacilli of the " ty- 

 phoid group " (Bacillus typhi abdominalis and allied forms), the bacilli of 

 the "colon group" (Bacillus coli communis with its varieties and similar 

 bacilli of faecal origin). When one of these pathogenic bacilli is present in a 

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