1902-3.] Bacterial Contamination of Milk. 479 



Plates gave colonies of: — 

 B. subtilis. 

 Micrococcus (sp ?). 



II. An aged cow, dry for some time, the butcher not knowing the 

 exact length of time. Udder of a fair size, and well formed. All organs 

 apparently healthy and normal. 



Bouillon. Whey Peptone. 



Liver + + 



Plates gave colonies of: — 



B. lactis aerogenes. 



Proteus. 



Peptone. Whey Peptone. 



Udder — — 



III. An aged cow, dry for four weeks previous to slaughter. Udder 

 fair size. Organs normal and apparently healthy. 



Bouillon. Whey Peptone. 



Liver + + 



Gelatine plates gave colonies of: — 

 B. subtilis. 



A spore-bearing bacillus, which produces no effect in milk. 



Bouillon. Whey Peptone. 



Udder + + 



Gelatine plates gave cultures of: — 



Micrococcus varians lactis. 



These results, whilst agreeing with Ford's, are not sufficiently 

 authoritative to allow us to assert positively that the bacteria found in 

 the udders of the two cows came from the blood or lymph stream, rather 

 than through the teat, but in conjunction with the results obtained by 

 Ford, they threw doubt on the supposition that all udder infection 

 comes originally through the orifice of the teat. It is also noteworthy 

 that a spore-bearing bacillus belonging to the subtilis group, and several 

 micrococci were isolated by Ward from udder tissue. Another fact, 

 which is difficult to explain and which may possibly have some influence 

 on the bacterial content of the udder in its normal condition, is the 

 strong germicidal power of freshly drawn milk. This property was first 



