224 IMPORTANT VABIETIES OF FISSION-FUNGI. 



but did not especially stud3' it, designated it by the name 

 Bacterium lactis acidi for the first time, so far as we can 

 see, in December, ISiKi (C. B. L. ii, 777). Aside from 

 the question of priority, it is very impractical to introduce 

 a Bacterium lactis acidi, together with a Bacterium acidi 

 lactici. Besides, Leichmann has also called a longer, 

 slender, thermophilic, non-sporulating, acid-producing 

 variety Bacillus lactis acidi. Later than our name is also 

 Bacillus lacticus Kruse. Lately Kozai has introduced 

 Bacillus acidi paralactici (Z. H. xxxi, 337). 



Microscopic. — Short rods, 1/j. long, 0.5-0.6/i thick, in 

 pairs or shi_)rt chains ; at the ends somewhat pointed ; 

 stains by Gram's method ; non-motile, facultative aerobe. 

 Upon the gelatin -plate: Punctiform colonies, never more 

 than 0.5 mm. in diameter uporL medium which does not 

 contain sugar ; when sugar is added, they are a little 

 larger, but always ^•ery delicate, and never liquefying. In 

 the stab culture there is often scarcel}' anything but a deep 

 growth. Upon the nf/ar plate : Delicate transparent growth, 

 like the finest dewdrops. In bouillon : Slight cloudiness 

 when no sugar is present, marked turbidity when sugar or 

 milk are added. 3[illc : Coagulated ; reaction strongly 

 acid. From grape- and milk-sugar pure dextrorotatory 

 lactic acid (no other acid) is produced, but no gas. 

 Upon potato there is a limited growth. 



Distribution. — According to Leichmann, Giinther, 

 Thierf elder, and Kozai, it is found in abundance in all 

 spontaneously coagulated milk, and is either the general 

 producer of lactic acid or, at least, the most important for 

 certain places and times. Yet the single fact that spon- 

 taneously soured milk contains preponderantly the long- 

 known inactive fermentation lactic acid, shows that other 

 varieties besides the Bact. Giintheri are concerned in the 

 process. Compare Leichmann (C. B. L. ii, 777). 



Kozai (Z. H. xxxi, 337) has demonsti'ated for Halle 

 that, especially at higher temperature, two varieties, which 

 produce lactic acid, work together. They are given the 

 names Bacillus acidi laevolactici and Micrococcus 

 acidi paralactici liquefaciens Halensis. By this last 

 name the necessit)' of the binomial nomenclature might 

 be strikingly pointed out. Why not Micrococcus 



