2Q2 



If the latter is done, two distinct forms call attention, which on a former 

 occasion I named 1 ) Lactobatilhis caucasicus and L. longus. Without attributing a 

 special value to this classification I yet wish to keep to it as I think that the 

 facts to be mentioned are fairly well comprised thereby. 



The longusgroup is characterised by its not acting on maltose, so that in 

 maltextract no, or very little acid it formed, but it does decompose milksugar. 

 In milk the forms of this goup, if grown after a previous culture of Lactocoecus 

 which has produced 5 to 8 c.c. of lactic acid per 100 c.c. of milk, will once more 

 produce a certain, even a like quantity of acid so that ca. 16 c.c. may be titrated, 

 the latter amount being however an exception. Generally no evolution of car- 

 bonic acid is observed but sometimes it is, and then so much gas can arise that 

 a milk beverage is acquired foaming like champagne. 



By a series of transitions, the longus forms obtained at 40 C., are joined 

 with lactobacilli which at a lower temperature find their optimal vital conditions, 

 but which are rarer in milk. 



The caucasicus group comprises those lactobacilli, which are able, indepen- 

 dently of lactococci to produce in milk a very high acid formation. At 37 to 

 40 C. it is possible after three days of their action to titrate 20 to 25 c.c. of 

 normal acid per 100 c.c. of milk. When that amount is reached further acid 

 formation stops. In this case, too, there is a parallel form which, beside much 

 lactic acid, also evolves carbonic acid. What by-product is then formed from the 

 lactose molecule beside the carbonic acid is not yet clear; probably it is aethyl- 

 alkohol. G. Bert rand has proved that these ferments can produce succinic acid. 

 They greatly owe their notoriety to their presence in kephir, which subject I 

 have touched before 2 ). Later however I have come to the conclusion 3 ) that 

 their distribution is by no means restricted to kephir only, but that they also 

 occur in our climate, sometimes in buttermilk, in cheese and even in common 

 baker's yeast. 



6. Yoghurt and maya. 



The use of soured milk as drink and food is so familiar to many Eastern 

 countries, and dates from so remote an antiquity that there can be no doubt as 

 to its favourable effect on health, and the establishment of various societies which 

 try to popularise new preparations of that nature, seems to prove that te atten- 

 tion of the Western nations begins to be drawn towards it. 



Both in the preparations of the Eastern nations and in those of industry 

 are always found lactic acid ferments of the genus Lactobacillus, mostly of Lacto- 

 coecus too. These lactic acid ferments alone determine the character of the leben 

 raiib of Egypt*), of the yoghurt of Bulgary"'), and probably also that of the 



') Sur les ferments lactiques de 1'industrie. Archives Neerlandaises. Ser. 2, T. 6, 

 p. 212, 1901. 



2 ) Sur le Kefyr. Archives Neerlandaises. I. 23, p. 428, 1891. 

 *) Ferments lactiques de 1'industrie 1. c. 



4 ) Annales de 1'Institut Pasteur. T. 16. p. 65, 1902. 



5 ) Massol et Grigoroff, Revue medicale de la Suisse romande 1905, p. 716. 

 Bert rand et We is vv ei Her , Action du ferment Bulgare sur le lait. Ann. de I'lnstitut 

 Pasteur, T. 20, p. 977, 1906. 



