358 IMPORTANT VARIETIES OF FISSION-FUNGI. 



sixteen days; in rare cases living vibrios have been found after forty- 

 seven days (Rommelaire). 



(b ) In cholera stools the vibrios are usually alive after one or two 

 days; more rarely, twenty to thirty days; still more rarely, longer; 

 in one instance they were alive for one hundred and twenty days. 

 Very similar results obtain in the case of clothing which is kept moist. 



(c) In cultures: The cholera vibrio belongs among the varieties 

 which die out easily. According to Gottschlich and Weigang, the 

 number of living individuals in agar streak cultures very rapidly 

 diminishes (Z. H. xx, 376). 



Yet living individuals are usually found in cultures three months 

 old, still frequently in those six months old, and now and then in 

 those one year of age, if only too extreme drying is avoided. Morpho- 

 logically such cultures consist almost entirely of involution forms. 

 (Compare 51, iv. ) According to Hiippe, also arthrospores. 



(d) In water: Very different results have been obtained by writers 

 as regards the viability of cholera vibrios when introduced into 

 unsterilized water, varying from one day to one year. Low tempera- 

 ture, exclusion of light, and the presence of salts favor preservation; 

 now and then, also, an increase is undoubtedly demonstrable. Most 

 often in well- and river-water death of the cholera vibrios is observed 

 in three to eight days. For more details see Ficker (Z. H. xxix, 1). 

 According to Hankin, the water of many Indian rivers kills cholera 

 vibriones very promptly; these waters are said to contain " certain 

 volatile, acid substances." 



(e) Upon foods, usually a few days; coffee, one hour; beer, one or 

 two hours; red wine, ten minutes. For further details compare 

 Uffelmann (Berl. klin. Wochenschr., 1892, 1209) and Friedrich (A. G. 

 A. vin, 87). 



Resistance to : 



(a) Desiccation : Some statements are found on page 41 ; the entire 

 literature is given by Ficker. Uffelmann upholds and William 

 contests the possibility that currents of wind occasionally may dis- 

 tribute living cholera vibriones in a partially dried state. 



(6) Moist heat: Killed in ten minutes at 60°. 



(c) The resistance to cold is given very differently by various 

 authors. All German investigators found them to withstand even 

 very low temperatures for a short time, but our winter cold (5°-10°) 

 was found sufficient to destroy them, often even in three, always in 

 eight, days (Renk, Uffelmann, etc.). 



Others, especially Russian writers, found greater resistance. Thus, 

 Kasansky claims that neither a short exposure to a temperature of 30°, 

 nor the operation of four months of Russian winter and repeated 

 freezing and thawing, completely destroys the cholera vibrio. Similar 

 results were yielded by experiments with Vibrio Proteus, tyrogenes, 

 etc. (C. B. xvn, 184). 



(d ) For the effects of disinfecting agents see Kasansky (C. B. xvn, 

 506). The resistance is slight; especially acids are poorly borne. 

 Iodoform vapor injures the cholera vibrio more than the other vibrios 

 (Buchner, Bujwid). 



