ROBERT S. BREED 383 



This is the Vibrio syncyaneus Ehrenberg' or Vibrio cyanogenus Fuchs.^ Because the 

 bright Berlin-blue chromogenesis is developed in a very characteristic way in milk in 

 which other bacteria have produced acid, and not in sterile milk, it is still recogniz- 

 able today.^ 



The earlier investigators described spores for this organism; but recent authors 

 (Heim/ Hammer^) deny their presence and describe the organism as having four polar 

 flagella. It is said to be variable in its liquefaction of gelatin, is gram negative, and 

 resembles in a general way the organism commonly known as Pseiidomonas fltiorescens 

 Migula. Outbreaks of blue milk are uncommon, only two outbreaks being noted by 

 Hammer as having occurred in America. While it is of much historical interest, it has 

 little practical significance. 



Other blue-milk organisms are Bacterium coelicolor Miiller and the organism de- 

 scribed by Mildenberg/' Bergey' has given the unfortunate name Pseudomonas cyano- 

 gena to the latter species, having retained the true blue-milk organism in the genus 

 Bacillus under the name B. syncyaneus because of the common statement that it forms 

 spores. 



NORMAL SOURING OF MILK 



Quite naturally the second species of milk bacteria to be recognized as distinct was 

 Bacterium lactis Lister (1873). This is now generally placed in the genus Streptococcus, 

 the synonomy of this much-named organism being as follows: 



Streptococcus lactis (Lister) Lohnis^ 



Synonyms: Bacterium lactis Lister, 1873, p. 408, 1878, p. 184;? Streptococcus acidi 

 lactici Grotenfelt, 1889, p. 185;? Micrococcus acidi paralactici Nencki and Sieber, 1889, 

 p. 532; "Bacillus No. 19" Adametz, 1889, p. 250; Bacillus acidi lactici Giinther and 

 Thierfelder, 1895, p. 195, and Esten, 1896, p. 44 (Not "Milchsaurebacterium" Hueppe, 

 1884, p. 340; Not Bacterium acidi lactici Zopf, 1883, p. 60, Grotenfelt, 1889, p. 123, 

 Kruse, 1896, p. 357; Not Bacillus acidi lactici Zopf, 1885, p. 87, and numerous others); 

 Bacterium gilntheri Lehmann and Neumann, 1896, p. 197; Bacterium lactis acidi 

 Leichmann, 1896, p. 778 (Not Bacterium lactis acidi Marpmann, 1886, p. 120); "Der ovaler 

 coccus" Freudenreich, 1895, p. 171, identified as Leichmann's organism by Freudenreich, 

 1899, p. 247, the latter being incorrectly called Bacillus acidi lactici. Correctly named Bac- 

 terium lactis acidi, 1902, p. 679, but called B. lactis acidi on pp. 680 &.; Bacillus lacticus Kruse, 

 1896, p. 356; Bacterium lacticus Chester, 1897, p. 88; Bacillus acidi lactici I Esten, in Conn, 

 1899, p. 52; Bacillus acidi paralactici Kozai, 1899, p. 372; Bacterium lacticum Migula, 1900, 

 p. 405; Bacterium truncatum Migula, 1900, p. 407 (Bacillus No. 19, Adametz); Lactococcus 



' Ehrenberg, C. G.: Ber. u. Verh. d. Konigl. Preuss. Akad. d. Wissens., Berlin, 5, 197. 1840. 



* Fuchs, C. H.: Mag. f. gesam. Thierheilk., 7, 133. 1841. 



^ The even more striking blood-red chromogenesis of Serratia marcescens Bizio (1823) (Zaogalac- 

 tina imetrofa Sette [1824], Monas prodigiosa Ehrenberg [1848]) caused this food spoilage bacterium 

 to be recognized earlier than the blue-milk organism, while the packet formation of Sarcina hitea 

 Goodsir (1842) made this a close third in order of recognition. 



'' Heim, L. : Lehrbuch der Bakteriologie (5th ed.). 1918. 



'Hammer, B. W.: Iowa Agric. Expcr. Sta. {Ames) Research Bull. i§. 1914. 



^Mildenberg, H. : Centralbl. f. Bakteriol., Abt. II, 56, 309. 1922. 



'Bergey, D. H. : Manual of Determinative Bacteriology (2d ed.). 1925. 



*L6hnis, F.: Centralbl. f. Bakteriol., Abt. II, 22, 553. 1909. 



