2/2 AGRICULTURAL BACTERIOLOGY. 



But the most recent work indicates that this objection will 

 not hold, and that perfectly normal cheeses may be made even 

 from pasteurized milk. If such milk is inoculated with a little 

 normal cheese of the quality desired, the cheese made there- 

 from ripens normally. The normal ripening from such milk 

 by the use of pure bacteria cultures has not yet been attained ; 

 but the possibility of a normal ripening after such a treatment 

 certainly indicates that there is nothing in the way of a practi- 

 cal application of pure bacteria cultures to cheese-making. It 

 must always be remembered, however, that since the ripening 

 process is in considerable degree due to the action of enzymes, 

 it will probably be impossible to produce a normal ripening by 

 the use of bacteria cultures alone. The microorganisms are 

 needed to produce the proper flavors, but the enzymes are also 

 needed to induce the normal chemical changes which should 

 take place during the ripening. The great financial interests 

 connected with the cheese industry have attracted quite a num- 

 ber of bacteriologists to the study of the problems, and most 

 dairy bacteriologists at the present time are working upon 

 various phases of the problem of the ripening of cheese. 



REFERENCES. 

 GENERAL DAIRYING. 



DUCLAUX. Principes de Laiterie. Also Le Lait. Paris, 1887. 

 FREUDENREICH. Die Bakteriologie in der Milchwirtschaft. Jena. 

 KrssELL. Outlines of Dairy Bacteriology. Madison, Wis., 1894. 

 \\KIGMANN. Milchztg. 1896, pp. 147, 163, etc. 



Soi RCES OF MILK BACTERIA. 



BACKIIAUS and APPEL. Ber. d. land. Inst. d. Univ. Konigsburg, 1900, p. 73. 

 Bm.i.KY and HALL. Cent. f. Bact. u. Par., II., I., 1895, p. 778. 

 DUNHAR. Milchztg. 1899, pp. 51, 753, etc. 

 PLAUT. Zeit. f. Ilyg., XXX., 1899, p. 52. 

 RKNK. Munch, med. Woch., \X\VIII., 1891. 



SlM>N. Hyg. |< u nd. f 1900, p. 71. 



WARD. Cent. f. Bact. u. Par., II., V., 1899, p. 411. 

 S in i UI.KN. Cent. f. Bact. u. Par., I., XI., 1891, p. 53. 

 S< in i i/. Arch. f. Hyg., XIV., 1892, p. 260. 



