BACTERIA COMMONLY tfOUND IN COWS* MILK. 103 



ticed on gelatine-plate cultures. The colonies soon sink 

 in the dissolved gelatine; they generally appear surrounded 

 by a more or less fluorescent zone. In gelatine " stick " 

 cultures of this kind the gelatine is dissolved in a funnel 

 shape, and the surface then first fluoresces strongly, and 

 later is covered by a greenish film. On agar-agar a green- 

 ish-white deposit is formed. Even in beef -broth a green 

 coloration is observed. This bacterium causes no acidity 

 in milk, but produces a complete precipitate of casein by 

 alkaline reaction (seldom by neutral reaction) ; a more or 

 less pronounced disagreeable rotten smell, furthermore, ap- 

 pears in the substratum. In many respects this bacterium 

 seems to resemble Fliigge's Bacillus fluorescens liquefa- 

 ciens. As mentioned above it is often met with in manure 

 particles, especially if these are very moist. I have also 

 found it in stagnant water. Sunlight and even daylight 

 seems to kill the organism within a short time. 



2b. Bacteria Coagulating Casein and Subsequently 

 Peptonizing the Coagulum. This subdivision has not, 

 according to my experience, many representatives in our 

 country. The bacteria spoken of above as resembling 

 the blue-milk bacillus belong here. Another represen- 

 tative of this subdivision was found last winter in a sam- 

 ple of milk from Helsingfors. The casein in this milk 

 did not coagulate, but the whole milk assumed a jelly- 

 like consistency, became fibrous and coherent, and turned 

 a grayish and afterwards a brownish color. Later on this 

 jelly-like mass gradually dissolved. The bacteria causing 

 these changes were isolated and found to be a long, 

 staff -like bacillus which often appeared in coherent chains. 

 Inoculated in sterilized milk it produced a strong alkaline 

 reaction, and otherwise changed the milk as stated above. 



