62 Agricultural Bacteriology. 



more frequently noted in pasteurized milk and craam 

 than elsewhere. Low temperatures also favor the growth 

 of certain of the types causing the trouble. 



Colored milk. Red milk is of frequent occurrence 

 and is most often due to the presence of blood which has 

 gained entrance to the milk ducts through a wound in 

 the udder. The presence of the blood can be recognized 

 with ease as the red blood corpuscles, that give the blood 

 'its color, are heavier than the milk serum and therefore 

 settle to the bottom of the milk receptacle. "When the 

 color is due to the presence of blood, the milk will be col- 

 ored when it is drawn. 



There are other changes that may occur in which a 

 reddish coloration may develop, due to the growtli of bac- 

 teria. Such troubles are rare and have but little eco- 

 nomic importance. Other pigment-forming bacteria oc- 

 casionally develop in milk causing abnormalities as to 

 color. 



Treatment of abnormal fermentations in milk. If 

 the milk from a dairy is constantly contaminated with 

 bacteria causing undesirable changes to such an extent as 

 to injure the milk for butter and cheese, some remedial 

 measures must be taken. In most cases a thorough 

 cleaning of the milk utensils on the farm, the cleaning of 

 the milk-room and the barn, together with the exclusion 

 of the cows from mud-holes, ponds and creeks will suf- 

 fice. "When these measures do not succeed, recourse must 

 be had to the employment of disinfectants, the use of 

 which will be described elsewhere. 



The discovery of the source from which the harmful 

 organisms come is an important thing, for little can be 

 done toward overcoming the defects until that is known. 



