462 MICRO-ORGANISMS AND DISEASE [chap. 



any case of suspected cholera the flakes of the intestinal 

 fluid or evacuation contain the vibrios in the typical distribu- 

 tion and in almost a pure condition such a case can 

 without further hesitation be declared as cholera asiatica; 

 those who have had sufficient experience of microscopic and 

 cultural experiments of numerous cases of cholera can but 

 confirm Koch's statement. Subsequent cultivations con- 

 firm the primary diagnosis. It must be obvious that if 

 there be sporadic, not typical cases, from which by the 

 culture test vibrios are isolated which in many respects 

 resemble, in others shghtly deviate from, the typical Koch's 

 vibrio, an unfailing test by which these vibrios could be 

 shown to be or not to be the true cholera vibrios would be 

 invaluable, and in much higher degree would such a test be 

 invaluable in the case of vibrios which like the above-quoted 

 water vibrios cannot be shown to have been directly derived 

 from cholera cases, and which owing to slight cultural 

 difierences are declared not to be cholera vibrios. Pfeififer 

 maintains that his test does furnish this important and unfail- 

 ing evidence : the vibrios, no matter what their slight cultural 

 differences be, that are derived from true cholera cases, give 

 his test, therefore are true cholera vibrios ; the vibrios, how- 

 ever, no matter how similar they be in morphological and 

 cultural respects to the Koch's vibrio, that are not derived 

 from cholera cases, do not give his test, are therefore not 

 cholera vibrios. Without wishing in the least to deny 

 Pfeiffer's justification in formulating so definitely his con- 

 clusions, nor wishing to accept unconditionally and in full 

 • — for reasons presently to be stated — Pfeiffer's statement, it 

 is at the outset only fair to draw attention to the following 

 hitherto unexplained facts of the Massowah vibrio. 



Pasquale had a few years ago sent to Pfeiffer and to 

 Metchnikoff cultures obtained from cases assumed to be 



