THE KINDS OF MICRO-ORGANISMS IN MILK 371 



other observers. Whether this is due to the fact that he studied 

 a larger number of strains or to some other reason cannot be de- 

 termined, and the decision must be obtained by future work. 



The nature of the coagulum formed by the different strains 

 varies somewhat. Some strains produce a smooth semifluid, 

 sometimes slimy coagulum without separation of whey, while 

 others produce a coagulum that is fairly firm and from which a 

 small amount of whey separates. 



Attempts at organizing the lactobacilli into groups have not 

 been wanting. Lohnis distinguishes six types, as follows: 



1. Type: Bacillus casei, Freudenreich. Coagulate milk and 

 form gas. Members of this type are: Bacterium casei d, Freuden- 

 reich; Lactobacillus caucasicus, longus and fragilis, Beijerinck; 

 Bacterium pabuli acidi III, E. Weiss. 



2. Type: Bacterium casei, Leichmann. No gas formed and 

 milk coagulated. Members of this type are: Bacterium casei I 

 to III, Leichmann and Bazarewski; Bact. pabuli I and II, E. 

 Weiss; Bact. casei a, Freudenreich; Bact. lactici aerobans, Conn; 

 Bact. No. XIX, Adametz (Bact. truncatum, Migula); Strepto- 

 bacillus lebenis, Rist and Khouri; Bact. bulgaricus, Liirssen and 

 Kiihn; Bact. lactis acidi, Marpmann; Bact. Eckles, from Harz 

 cheese; Bact. Listeri and Wortmanni, Henneberg. 



3. Type: Bacterium caucasicum, Lehmann and Neumann. 

 Form gas, but do not coagulate milk. Members of this type are : 

 Bacillus from kefir, Freudenreich; Lactobacillus fermentum, Bei- 

 jerinck; Bacterium panis fermentati, Heyducki, Buchneri and bras- 

 sicse fermentata^, Henneberg. 



4. Type: Bacterium delbriicki, Leichmann. Does not form 

 gas and does not coagulate milk. Members of this type are: 

 Bact. delbriicki, Leichmann; Bact. acidificans longissimus, Lafar; 

 Long bacilli from sour dough, Holliger; Bact. lebenis, Rist and 

 Khouri; Bact. Leichmanni I-III and Beijerinckii, Henneberg. 



5. Type: Slimy type. Members of this type are: Varieties of 

 Bacterium lactis acidi, Leichmann; Lactobacillus caucasicus, 

 Beijerinck; Bacterium casei o and e ; Bact. abderholdi, Henne- 

 berg, and a strain from Yoghurt. 



6. Type: Forms colonies with branches. Members of this 

 type are: Bacterium lactis acidi, Leichmann; Bact. casei d and e, 

 Freudenreich; Bacilli from mazun described by Diiggeli and by 

 Weigmann, Gruber, and Huss; Granule bacillus of Liirssen and 

 Kiihn; Bact. yoghurt, Kuntze; Bacillus from kumiss described 

 by Schipin; Bact. sardous, Grixoni; Lactobacillus conglomeratuus, 

 Beijerinck; Bacterium delbriicki d, Henneberg; different bacilli 

 from lactic acid in stomach. 



This classification undoubtedly might be simplified by an ex- 



