300 MICROBIOLOGY 



Milk. There is rapid coagulation and acid formation. It 

 is characteristic of this bacterium that it can produce a large 

 amount of acids, chiefly lactic, without being injured by them. 



Life conditions and properties. It is an aerobe and facul- 

 tative anaerobe. It grows readily at temperatures between 

 24 and 30 C. It is not known to produce any specific toxin. 

 It coagulates milk readily. 



Pathogenesis. Different strains of this bacillus vary 

 much in their pathogenicity for animals. Wilde claims that 

 it is more pathogenic for white mice and guinea pigs than is 

 the bacillus of Friedlander. He speaks of it as the most viru- 

 lent member of this group. Kraus, writing in Fliigge's 

 ' ' Mikroorganismen, " rates its pathogenicity less high. 



Closely related to this bacillus, as well as to those of the 

 Friedlander group, is an encapsulated bacillus isolated from a 

 case of broncho-pneumonia by Mallory and Wright 3 which is 

 extremely pathogenic for mice, guinea pigs, and rabbits. 



BACTERIUM ACIDI LACTICI (HUEPPE) MIGULA. 



Synonyms. Bacillus acidi lactici Hueppe. 



Place in nature. This organism was studied in 1884 by 

 Hueppe x but it had previously been discovered by Groten- 

 felt 2 in sour coagulated milk. Esten quotes the following : 

 "In the year 1877 Lister, by means of a capillary pipette to 

 which was attached a screw-head so adjusted that he could 

 force out 1-100 of a drop of a diluted solution of milk, ob- 

 tained the first pure culture of a milk souring organism, which 

 he named Bacterium lactis. Lister thus has the honor of 

 being the first to discover and isolate as a pure culture this 

 organism." The phenomenon of sour milk has been studied 

 by a large number of bacteriologists. Esten 3 has pointed out 

 very clearly the large number of bacteria which have been 



3 Mallory and Wright. Zeit. f. Hyg., Bd. XX (1895) p. 220. 



1 Hueppe. Mittheil. a. d. Kaiserl. Gesundheitsamte, Bd. II 

 (1884) p. 309. 



2 Grotenfelt Fortschritte d. Medizin, 1889, p. 121. 



* Esten. Bulletin No. 59, Storrs Agric. Exp. Station, Storrs, 

 Conn., 1909. 



