PART I.] Nature of the " Comma-shaped Bacillus y 333 



mounted in dammar varnish or Canada balsam dissolved in benzol, and should be 

 examined under a ^th or xe^^ of an inch oil-immersion lens. 



As in choleraic discharges so in the saliva, the number of the comma-shaped 

 bacilli will be found to vary greatly in different persons, and at different times in 

 the same person. Sometimes only one or two " commas " will be seen in the field, 

 at others a dozen may be counted, and, occasionally, little colony-groups of them may 

 be found scattered here and there throughout the slide. 



It may be remarked in passing, and as bearing upon what has been already 

 said regarding the general absence of comma-shaped bacteria from the intestinal 

 mucosa itself, that they do not appear to manifest any special tendency for attacking 

 the decaying epithelial scales of the mouth, but that, on the contrary, they are 

 for the most part found free in the fluid, the epithelium being studded with other 

 bacterial forms. 



Persons who have not been in the habit of examining dried saliva-films will 

 probably be surprised at the number and variety of the organisms which are, more 

 or less, constantly to be found in the mouth, and especially at the number of spirilla 

 with which the fluid is generally crowded. 



The alvine discharges in cholera sometimes swarm with precisely similar spiral 

 organisms, and indeed, as has long been known, the fluid exuded into the intestines 

 in this disease is peculiarly suitable for the growth of these and allied microbes. But, 

 so far as my own experience — dating from 1869 — of the microscopic examination of 

 such a fluid goes, all the microphytes ordinarily found in it are likewise to be found, to 

 a greater or less extent, in the secretions of the mouth and fauces of unaffected 

 persons. And with reference to the comma- like bacilli found in cholera, to which 

 such virulent properties have been ascribed, I shall continue to regard them as 

 identical in their nature with those ordinarily present in the saliva until it has 

 been clearly demonstrated that they are physiologically different. 



[This memorandum was originally published in the Lancet of Sept. 20th, 1884, 

 through the courtesy of the Director-General of the Army Medical Department, Sir 

 Thomas Crawford. " The culminating point of importance in the memorandum is the 

 announcement that curved or comma-shaped bacilli, identical in size, form, and in their 

 reaction to aniline dyes with those found in cholera, are ordinarily present to a greater 

 or less extent in the secretions of the mouths of perfectly healthy persons " {I. c. p. 497).] 



