TYl'liS U1-- UACTEKIA FOUND IN MILK 55 



SOAPY MILK 



A somewhat peculiar infection in milk has been discovered in 

 one or two cases in Europe, and has been called soapy milk; 

 but it has not, so far as is known, occurred in America. The 

 milk in question develops a slight soapy taste which is decidedly 

 unpleasant. Two different species of bacteria (Bact. sapolacti- 

 ciim and B. lactis saponacei} have been isolated from such milk, 

 and have been proved to produce the trouble. The phenomenon 

 is of no special significance, at least in American dairies. 1 



OIDIUM LACTIS 



This organism is very widely distributed and plays an im- 

 portant part in certain dairy processes, although it has very 

 little or no relation to milk used as milk. It differs from other 

 bacteria in appearance and method of growth (Fig. 29), and 

 seems to be about half way between a bacterium and a mold. 

 Like molds, it grows generally upon the surface of liquids and 

 solids, and does not, like bacteria, penetrate into their depths. 

 \Yhen growing upon the surface it produces long, delicate 

 threads, which radiate from a central point where the growth 

 starts and extends over the surface of the medium for consider- 

 able distances. At first it looks exactly like a mold, but, after 

 growing for about two days, these threads break into a large 

 number of very short segments, which serve as spores; for 

 they will grow and generate into fresh threads, if planted upon 

 favorable places. The organism grows with extreme rapidity, 

 and when planted on the surface of hardened milk, like a soft 

 cheese, it will spread over the surface so rapidly that, in the 

 course of a very few hours, it may cover the whole surface. 

 For this reason, it is found to be one of the obstacles to the 



1 Eicholz. Cent. f. Bact., II., ix., p. 631, 1902. 

 Weigmann and Zirn. Cent. f. Bact., xv., p. 463, 1894. 

 Marshall. Bui. 146, Mich. Exper. Sta. 



