190 BACTERIOLOGICAL EXAMINATION OF WATER. 



B. Typhosus Simulans (Houston). 



The following organisms which I have recently isolated from 

 a polluted water are even more difficult, as some of these react 

 to anti-typhoid serum : 



B. Typhosus Simulans (Culture A.). 



Gelatine Plates. The surface colonies appeared as thin bluish 

 films with an irregular margin. Under a low power the centre 

 of the colonies had a yellowish tinge, and surface markings of 

 ridges and valleys were seen running out from the centre to the 

 periphery. 



Gelatine stab. Surface growth resembled the colonies ; a thin 

 white growth along the stab. 



Milk. Unchanged after a month. 



Litmus-whey. Faint acidity, requiring less than 6 per cent. 



of -^ alkali to neutralise it. 



Glucose-gelatine Shake. No gas formation. 



