CHAPTER XIV. 



QUALITATIVE ANALYSIS continued. 



SPIRILLUM CHOLEILE ASIATICS. 



THIS micro-organism was first isolated by Koch, in 1883, from 

 the stools of cases of cholera which he investigated in Egypt. 

 Later, more extended researches were made in India, and Koch 

 came to the conclusion that the association of this microbe 

 with Asiatic cholera was constant. 



On cultivation the following appearances are seen on the 

 various media : 



Gelatine Plates. In twenty-four to forty-eight hours the 

 colonies appear as minute white points, w r hich under a low power 

 show an irregular or furrowed margin. Later, liquefaction 

 of the gelatine is produced, and the colonies sink into small 

 cups formed by the liquefaction ; the plate then shows small 

 sharply-marked rings around the colonies. After about seventy- 

 two hours, owing to the increasing liquefaction, the colonies 

 appear as granular masses, with torn or broken up margins, lying 

 in the bottom of circular cups of liquefied gelatine. The 

 granular masses gradually became fainter, and the whole surface 

 of the plate is completely liquefied. 



Agar Plates. Under a low power the surface colonies appear 

 as circular discs of brownish-yellow colour, and are more trans- 

 parent than the colonies of most other organisms. 



Gelatine-stab. During the first twenty-four hours the growth 

 is hardly perceptible, but in forty-eight hours slight liquefaction 

 with excavation of the gelatine is seen at the surface of 

 the stab, and below this a white growth appears along the line 

 of inoculation. About the fourth day a bubble-shaped 

 depression is seen at the surface, and below this a funnel of 

 liquefaction, covered at the surface with a white growth. 



