xvi] VIBRIO AND SPIRILLUM 459 



the tank, as previously stated, oysters kept therein for four 

 days and for nine days respectively — the tank being daily well 

 irrigated with fresh filtered sea water — yielded in peptone 

 salt cultures from their interior liquor and body substance 

 positive results,^ that is to say, yielded cultures of vibrios, but 

 though in many respects they resembled the cholera vibrios 

 added to the tank water, yet in some important points they 

 differed markedly from them as also from one another, and 

 retained these differences constant through subcultures. 



In another series in which 'oysters were kept for four 

 days in cholera-infected sea water the peptone culture 

 yielded vibrios which possessed distinct differences, retaining 

 them in subcultures, not only from the original vibrios 

 employed for the experiment, but also from those 

 obtained from the previous two sets of oysters. The 

 conclusion which these observations justify seems to be 

 that in the bodies of oysters vibrios, which had an un- 

 doubted cholera origin, become markedly altered and be 

 come possessed of certain apparently permanent characters 

 not possessed by the vibrios previously. I cannot here 

 enter into the details of these observations, as these will 

 be published in the Reports of the Medical Officer of the 

 Local Government Board, and must content myself with 

 the statement that I think a permanent alteration of the 

 characters of the cholera vibrio had been established. 

 If this be so, then the differences noted in many of the 

 vibrios discovered in various waters (Spree, Danube, Elbe, 

 Seine, &c.) after the visitation by cholera of the respective 

 countries, as also those discovered by Pestana in cholerine, 

 need not indicate that these vibrios were not originally cholera 



' The water of the tank was examined in the above-named manner 

 and was found to yield positive peptone cultures after four and after ten 

 days respectively. 



