B. TYPHOSUS 159 



oped as small grey dots. Milk was coagulated at 37 C. with 

 acid formation and a separation of the milk constituents into 

 a cream layer at the top, curd at the bottom, and whey in 

 between. On blood serum the colonies appeared on the third 

 day as depressions due to liquefaction of the medium. On 

 injection into guinea pigs, well-developed local abscesses ap- 

 peared in one to two weeks. Intra-peritoneal injection pro- 

 duced abscesses on the omentum and on the pancreas or around 

 the kidney. The author has, on several occasions, isolated 

 bacilli from milk that resembled B. diphtheria, but the majority 

 of these could be distinguished from the typical pathogenic 

 variety by the size. The most usual type was about 5/* in 

 length and slightly pointed at both ends; they retained the 

 stain when treated by Gram's method and gave a typical 

 barred appearance with Loeffler's methylene blue and Ponder's 

 stain. On agar, and on blood serum, the organisms developed 

 as small white opaque colonies. Gelatine was not liquefied. 

 Dextrose, lactose, saccharose, mannite, and dulcite were not 

 fermented and no visible change was produced in litmus milk. 

 They were non-motile and did not form spores; broth cultures 

 were non-pathogenic to guinea pigs when treated by the intra- 

 peritoneal method, 



No etiological connection has been discovered between 

 these diphtheroid bacilli and any pathological condition and 

 they must, therefore, be regarded as harmless saphrophytes 

 that are of no importance or significance in public health work. 



B. TYPHOSUS 



There are on record several hundreds of epidemics of 

 typhoid fever that are definitely attributed to milk as the 

 immediate source of infection, but there is, so far as the author 

 can ascertain, not a single authentic case recorded in which B. 

 typhosus has been isolated from milk suspected of causing an 

 epidemic. Typhoid infection of milk is of external origin and 

 whether it is due to a carrier, or to a person having the dis- 



