CHOLERA 207 



greatly congested, and the epithelium is usually to a great 

 extent detached in the shape of flakes. 



The flakes may contain large numbers of the 'commas,' 

 and it is frequently possible to report positively at once as 

 to the nature of the disease on the immediate microscopic 

 examination of one of these flakes, whether from the con- 

 tents of the ileum or in a living patient from the stool, 

 a minute fragment of one of the flakes being suspended 

 in salt-and-water, and examined by the hanging-drop 

 culture, when practice will enable the trained observer to 

 recognise the spirillum of Koch by its characteristic screw- 

 like movement. If a portion of a flake be crushed carefully 

 between two cover-glasses, which are then drawn apart and 

 stained, it will be found that in cases of cholera the 

 organisms lie with their long axis in the same direction, 

 and present what is known as the ' fish-in-stream ' appear- 

 ance. Klein has, however, found the same appearance to 

 be given by the B. coli comnnunis and the Proteus vulgaris 

 in cases of so-called English cholera. 



Such appearances are, however, only to be found in a 

 minority of cases, and it is generally necessary to perform 

 the following cultural experiments : Two or three gelatine 

 tubes are melted, cooled to 35° C, and then inocu- 

 lated and poured into plates, while at the same time some 

 tubes containing sterilised Dunham solution are inoculated. 

 (This solution consists of peptone 1 per cent., salt 5 per 

 cent, in distilled water.) The gelatine plates are examined 

 after forty-eight hours at 22° C, and the colonies produced 

 by true cholera are distinguishable by the appearance of 

 small funnel-shaped depressions in the gelatine, having 

 yellowish points at their apex, while the gelatine begins to 

 liquefy. Fragments of colonies having these characters are 

 picked out with a platinum needle for microscopic examina- 

 tion, both in the hanging-drop culture and in cover-glass 



