268 MODERH DAIRY PRACTICE. 



retards their progress, while molds thrive and act 011 the 

 cheese. After sometime the mold vegetation assumes a 

 bluish color, and the color of the cheese turns reddish 

 yellow. If the air grows too moist, these molds will die 

 and the putrefactive bacteria will take their place, thus 

 spoiling the cheese. If sunlight strikes the molds, they 

 will also die and fermentations are stopped. After some 

 time e.g., with the Camembert cheese in twenty-five days 

 the cheese is brought from the curing-room into the 

 cheese- cellar, which is usually built half underground and 

 so arranged that its temperature will remain fairly constant 

 at 54-5? F. (12-14 C.), and that direct sunlight and 

 draught are avoided. The activities of the molds are here 

 soon checked and the work of the bacteria proper begins. 

 These are now in position to multiply immensely. 

 Adametz found the usual bacteria content of Swiss cot- 

 tage cheese (Hauskdse) 2-5 millions per gram. 



At the present stage of our knowledge of the action of 

 bacteria in the curing of cheese it would hardly be advis- 

 able to give a more detailed account of the morphology 

 and other characteristics of the separate cheese-bacteria 

 which have so far been identified. There are still many 

 points in the complicated processes of manufacture, and 

 especially in the curing of cheese, which are not yet 

 worked out, and the nature of several of the bacteria iso- 

 lated have not been sufficiently studied in detail. About 

 fifty different forms are at the present included among 

 the so-called cheese-bacteria, and this number will doubt- 

 less be considerably increased when further study has been 

 made. In the curing of different kinds of cheese different 

 forms of bacteria are evidently at work. Of the ten forms 

 of bacteria which Duclaux found active in the curing of 



