414 CHOLERA 



be applied, and in many cases it is advisable to test the effects 

 of intraperitoneal injection of a portion of a recent agar culture 

 in a guinea-pig, the amount sufficient to cause death being also 

 ascertained. The agglutinating or sedimenting properties of the 

 serum of the patient should be tested against a known cholera 

 organism, and against the spirillum cultivated from the case. 

 The action of an anti-cholera serum, i.e. the serum of animal 

 immunised against the cholera spirillum, should be tested in a 

 similar manner. 



Up till recent times there had been cultivated from sources 

 other than cholera cases, no organism which gave all the cultural 

 and biological tests (agglutination and Pfeiffer's reaction) of the 

 cholera spirillum. In 1905, however, Gotschlich obtained six 

 different strains of a spirillum which conformed in all these 

 respects. The organisms were obtained at El Tor from the 

 intestines of pilgrims who had died with dysenteric symptoms, 

 and there were no cases of cholera in the vicinity. The organisms 

 in question, however, differ from the cholera organism in having 

 marked hsemolytic action, and also in producing a rapidly acting 

 extra -cellular toxin. There has been diversity of opinion 

 with regard to the nature of these organisms, for while some 

 consider that they are a different species from the cholera 

 organism, others regard them as true cholera spirilla which had 

 been carried by the patients, although no symptoms of cholera 

 resulted from their presence. If they are not to be regarded as 

 cholera organisms, .we have the striking fact that they correspond 

 in the immunity reactions. This instance exemplifies well the 

 great difficulty which may surround the identification of a 

 particular organism obtained from non- cholera cases, and one 

 can hardly doubt that if cholera -like symptoms had been 

 present in the El Tor cases, the spirilla would have been accepted 

 as varieties of the cholera organism, though differing in their 

 haemolytic action. None of the facts ascertained, however, really 

 affect the question as to the causal relationship of Koch's spirillum 

 to cholera, although they indicate the difficulties which may 

 attend the bacteriological diagnosis in isolated cases of the 

 disease. 



General Summary. We may briefly summarise as follows 

 the facts in favour of Koch's spirillum being the cause of cholera. 

 First, there is the constant presence of spirilla in true cases of 

 cholera, which on the whole conform closely with Koch's 

 description, though variations undoubtedly occur. Moreover, 

 the facts known with regard to their conditions of growth, etc., 

 are in conformity with the origin and spread of cholera epidemics. 



