1902-3] Bacterial Contamination of Milk. 475 



small numbers, and the fact that the flavour was not strongly marked, 

 make this an inconsiderable item so far as the " natural ripening" of 

 such milk is concerned. 



Micrococcus V avians lactis {Qor\n 113 and 104). Conn, in speaking 

 of this coccus, considers it one of the most important of dairy species, 

 and suggests that it likely exists in the milk-ducts. 



Bacillus No. 18, Conn. This species appeared very frequently in 

 all samples examined, but never in very large numbers. In old gelatin 

 and agar cultures, spores appeared at the ends of the bacilli. Two 

 cultures from these heated for ten or fifteen minutes at a temperature of 

 85° to 90° germinated in one day. The species is very similar to 

 Bacillus No. 18 Comi, but differs in that growth on potato is not spread- 

 ing, and no spores are found in potato culture. 



Bacillus N'o. 7. This bacillus was quite constantly present for 

 some weeks, but afterwards disappeared. It seems to resemble B. 

 creuioris (./j) {B. lactis No. g Flugge), but differs in its effect on milk, so 

 that it would appear to be an allied species. 



Bacterium No. 8. The gelatine plate colony appears very similar to 

 No. 7, but the organisms otherwise differ, both morphologically and 

 culturally in many particulars. Like No. 7 it appeared quite constantly 

 for some weeks and then disappeared. 



B. exiguum (Wright).'" This bacterium was found almost con- 

 stantly present in the milk of one ot the cows tested, but was never 

 found in that of any other. There were never more than from one to 

 four colonies per plate present, so that its effect on the milk was very 

 inconsiderable. Its similarity to Bad. exiguum (Wright) is most marked. 

 Wright isolated this bacterium from water, but the fact that he found its 

 optimum temperature to be ^f^" and that it is a facultative anaerobe 

 does not make it at all surprising that it should be found in the udder of 

 a cow. 



Micrococcus No. 10. This coccus comes in the same class as Conn's 

 167, and may be identical with it. The most marked variations are the 

 gelatin colony, and the fact that in no culture of this germ was there the 

 slightest indication of a yellow colour. At the same time it agrees in 

 morphological characters, and especially in the fact that, although a 

 liquefying coccus, it fails to curdle milk. 



Like several of the forms previously described, this coccus was 

 found to be present for some time in the samples taken, but afterwards, 



