104 MODERtf DAIRY PRACTICE. 



Quite frequently the so-called potato bacillus Bacillus 

 mesentericus vulgatus is found in Finnish milk. This may 

 easily be recognized by its active power of locomotion, its 

 short, thick staff-shape, its strong peptonizing power, and 

 its great inclination to build spores. I have also found 

 represented in our Finnish milk the Duclaux Tyrothrix 

 family, some species of which resemble in several respects 

 the potato bacilli. The organisms belonging to this sub- 

 division generally have spores possessing great tenacity 

 of life; they easily withstand boiling temperatures. For 

 this reason their presence in milk is very injurious. Ac- 

 cording to Duclaux, the bacteria of this subdivision pro- 

 duce two substances : the one which he identifies with ren- 

 net precipitates casein, while the other again peptonizes it. 



This subdivision seems to be more numerous in milk 

 produced in southern countries than in our northern milk. 

 My investigations of South German and French milk 

 would show this; and also the constant appearance of milk 

 diseases, as red milk, blue milk, etc., which are caused by 

 infection of bacteria belonging to this subdivision, in sam- 

 ples of milk examined.* 



Zc. Bacteria bringing Casein into Fermentation with- 

 out Coagulating It. The final result of the activity in 

 milk of bacteria belonging to this subdivision is the same 

 as that of the families belonging to the last two sub- 

 divisions, viz., a solution of the casein through decom- 

 position. These subdivisions together form the group of 

 bacteria called putrefactive bacteria by older bacteriologists 



* For a description of bacteria belonging to this subdivision see 

 Scholl, "Die Milch," 1891, p. 42; Conn, "The Fermentations of 

 Milk," 1892, p. 48; Freudenreich, " Bakteriologie d. Milch wirt- 

 schaft," 1893, p. 45, etc. 



