THE TYPHOID BACILLUS. 213 



aminiag water bacberiologically have been entered into 

 fully in Chapter XIII. j it is not therefore necessary 

 to describe them here. Now and again in specimens 

 of suspected water, of which plate cultivations have 

 been made, we may come across colonies, which, 

 especially in their lemon-shaped appearance, have a 

 great resemblance to those of the typhoid bacillus. 

 Under all circumstances it is absolutely necessary to 

 make potato cultures of these bacteria. It may also \ 

 sometimes happen that milk is suspected of harbour- 

 ing typhoid bacilli, since widespread epidemics have 

 occurred, especially in Holland, which could only have 

 been caused by infected milk. The examination of 

 milk is essentially the same as that of water, only ia 

 this case very small quantities must be used for the 

 cultivations, since milk, even if it has only stood for 

 a few hours, harbours enormous quantities of bacteriaJ 

 at any rate, in warm weather. 



