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SUPPOSED INSTANCES 



[CH. IX 



gated at the date of the first examination (August 23rd). 

 Gaertner's bacillus was not found in any case and Aertryck's 

 bacillus in one case only. 



These experiments appeared to lend further support to 

 the theory that the two types of organisms were capable of 

 transmutation. It is necessary, however, again to emphasise 

 the fact that a negative result in the case of all but one of the 

 animals examined as a control, does not prove the absence of 

 organisms — it only proves their scarcity. A subsequent in- 

 crease in their numbers might at once have revealed their 

 presence. Such an increase might be apparent only, due to 

 a simple disturbance of the functions of the bowel, such as 

 diarrhoea, which would dislodge the organism from its usual 

 habitat, carry it to a lower part of the bowel and hasten its 

 evacuation. The increase in numbers might, on the other hand, 

 be a real one, brought about by a lowered vitality of the 

 body as a whole and local inflammatory changes. It is to such 

 factors that we attribute the enormous number of B. coli 

 found in the stools of patients suff"ering from cholera. 



All these factors were, no doubt, operative in the case of 

 the three guineapigs which were actually fed with the culture 

 of B. Gaertner and may explain the subsequent discovery of 



