BACTERIA AND CHEESE-MAKING. 259 



ripening of cheese differ in various kinds of cheese and 

 are caused by different forms of micro-organisms. The 

 intensity and duration of the fermentations are also differ- 

 ent in the various kinds. The soft kinds of cheese undergo 

 violent and radical fermentations, while certain kinds of 

 English cheese ferment only slightly and very slowly. 

 We find a smaller number of bacteria in the latter kinds 

 than in the former. Swiss cheese seems to stand nearer 

 the soft cheeses as regards the number of bacteria con- 

 tained in it and the intensity of the fermentations, but it 

 requires a rather long time for perfect ripening. 



"What dairy science at the present time knows of the 

 bacteriology of cheese-making is due above all to the inves- 

 tigations of Duclaux, Adametz, Weigmann, and v. Freu- 

 denreich.* The following account is based mainly on the 



* The following references include the main investigations of the 

 relation of bacteria to cheese- making published up to date : 

 ADAMETZ. Ripening of Emmenthal and Cottage Cheese. Landw. 



Jahrb., 18 (1893), p. 227. 

 The Causes of Abnormal Ripening Processes in Cheese. Milch- 



Zeitung, 1891, pp. 237-248 ; 1892, pp. 205-223. 

 BAUMANN. Studies in the Ripening of Cheese. Inaug. Dissert. 



Univ. Konigsberg, 1893 ; Landw. Versuchs.-Stat., 42, pp. 181- 



214 ; Exp. Sta. Record, 5, p. 249. 

 BENECKE. On the Causes of the Changes in Emmenthal Cheese 



during Ripening. Landw. Jahrb., 16, p. 359. 

 CONN. Isolation of Rennet from Bacteria-cultures. Storrs School 



Experiment Station Report, 1892, pp. 106-126. 

 DUCLAUX. Manufacture, Ripening, and Diseases of Cantat Cheese. 



Paris, 1878. 



Memoires sur le Lait, I-III. Paris, 1880-84. 



Microbes and Fat. Ann. de I'Inst. Past., 7 (1893), pp. 305-324. 



FKEUDENREICH. Ripening of Emmenthal Cheese. Landw. Jahrb. 



d. Schweiz, 4, p. 17 ; 5, p. 16 ; Centralbl. f. Bakt., 12, p. 335. 



