312 



The " Long Lactic Bacteria/' 



[JULY, 



The substances examined included — 



Leipzig ordinary market milk. 



Swiss Emmenthaler cheese. 



Deutsche cheese, Thiiringer Stangerkase. 



Cheddar cheese, from Scotland. 



Sauerkraut. 



Human saliva. 



Fasces of cows. 



Soil. 



The lactobacilli were proved to be present, in larger or 

 smaller numbers, in each of the substances examined. 



The medium employed seemed to encourage the growth 

 of the long forms, lactobacilli, relatively to other types. In 

 all cases microscopic examination of the yeast whey cultures 

 showed that the number of lactobacilli present, relative to 

 other types, was increased in the second culture of yeast 

 whey, which thus formed a very effective enriching medium 

 for this type of bacteria. In some cases the colonies of lacto- 

 bacilli were almost the only ones to be observed on the Petri 

 plates ; and in some cases the colonies were clearly visible to 

 the naked eye, along with a well-marked transparent zone 

 due to the dissolving of the chalk, after twenty-four hours' 

 incubation at 38 0 C. In other cases acid production was less 

 rapid, and the dissolving of the chalk appeared only after 

 several days. 



Subsequently the presence of lactobacilli in compara- 

 tively large numbers in the original substances, notably in 

 ordinary market milk, was proved in many cases by direct 

 microscopic examination. Indeed, germs which had pre- 

 viously, in microscopic examination, been taken for other 

 long forms, proved on a closer acquaintance to belong to the 

 lactobacilli group; and such bacteria were found to be far 

 more common than is generally supposed. 



Lactobacilli were found growing in colonies quite different 

 in appearance and outline in almost every gradation from the 

 irregular, filamentous structure — branched colonies — to the 

 common round, or oblong, or lobed colony. This tends to 

 confirm the conclusions of other workers.* The form of the 

 organism also varied from the ordinary short rod to the long 



* Lohnis, Centralblatt fur Bakter., Bd. l8, 1907; Rubinsky, Idem, Bd. 28. 



