354 BACTERIOLOGY. 



uations, prepare a cover-slip preparation in the ordinary 

 way and stain it. If, upon microscopic examination, 

 only curved rods, or curved rods greatly in excess of 

 all other forms, are present, the diagnosis of Asiatic 

 cholera is more than likely correct ; and particularly is 

 this true if these organisms are arranged in irregular 

 linear groups with the long axes of all the rods point- 

 ing in nearly the same direction, that is to say, some- 

 what as minnows arrange themselves when swimming in 

 schools up stream. (Koch.) 



In 1886 Weisserand Frank 1 expressed their opinion 

 upon the value of microscopic examination in these cases 

 in the following terms : 



(a) In the majority of cases microscopic examination 

 is sufficient for the detection of the presence of the 

 comma bacillus in the intestinal evacuations of cholera 

 patients. 



(6) Even in the most acute cases, running a very 

 rapid course, the comma bacillus can always be found 

 in the evacuations. 



(c) In general,- the number of cholera spirilla present 

 is greater the earlier death occurs ; when death is post- 

 poned, and the disease continues for a longer period, 

 their number is diminished. 



(d) Should the patient not die of cholera, but from 

 some other disease, such as typhoid fever, that may be 

 engrafted upon it, the comma bacilli may disappear 

 entirely from the intestines. 



II. With another slimy flake prepare a set of gelatin 

 plates. Place them at a temperature of from 20 to 

 22 C., and at sixteen, twenty-two, and thirty-six hours 



i Zeitschrift fur Hygiene, Bd. i., p. 397. 



