4i6 MICRO-ORGANISMS AND DISEASE [chap. 



vation are resorted to for confirmation. Unfortunately such 

 a condition is present only in a percentage of cases ; 

 amongst the fifty odd cases of Asiatic cholera occurring in 

 England in September and October of 1893 {see Tabular 

 Statement) such a condition was found in fifteen cases, that 

 is to say, when from the number and distribution of the 

 vibrios in the flakes of the intestinal contents alone the 

 diagnosis could be made. 



Koch's cholera vibrios or Koch's comma bacilli can be 

 demonstrated in almost all cases of cholera Asiatica, begin- 

 ning with those that show as yet only diarrhoea, more or 

 less profuse, up to those that have shown all the typical 

 characters, with vomiting and purging of copious rice-water 

 evacuations. After the acute stage has passed, and the 

 typhoid stage has set in, the comma bacilli become less 

 numerous, and gradually disappear, so that when after three, 

 four, or five days the evacuations assume again the character 

 of faeces the comma bacilli are either only found with diffi- 

 culty or are altogether missed ; in fact, in cases in which 

 they are scarce at the earlier stage they are not to be seen 

 later than the third day. 



If cholera stools, particularly rice-water stools, are kept for 

 a day or so, one meets with comma bacilli which have 

 formed spirilla ; some wavy threads, others distinctly cork- 

 screw-shaped, some short, others long ; in dried and stained 

 preparations many of these spirilla are seen to be chains of 

 comma bacilli ; spirilla are found occasionally already in 

 the fresh stools or fresh mucus flakes, but as a rule the 

 comma bacilli are present as single vibrios or as dumb-bell 

 vibrios, i.e., S-shaped forms. As regards the amount of 

 curvature and length of the individuals there exist varia- 

 tions. Moreover as cultures prove and as has been already 

 mentioned (see also Tabular Statement ^of Cholera Cases in 



