( 27 ) 



Real lactobacilli mostly appear after 2 or 3 days and then the 

 acid rises rapidly parallel to their multiplication to 20, even to 

 25 c.c. normal per J 00 c.c. of milk. When this degree of souring 

 is reached, there is usually no further increase observed, not even 

 after several days, and whenever this does take place, there should 

 be thought of aeration, by which the growth of vinegar bacteria 

 and acetic acid formation from alcohol, have become possible. 



The pure culture of lactobacilli is sometimes easy, in other cases, 

 with more anaerobic stuck'-, it is more difficult. Always, however, 

 it is troublesome with these pure cultures to obtain a considerable 

 souring in milk and there is most chance of success (but even then 

 the success is not quite certain) by souring lactobacilli together with 

 Lactococcua which serves for the first souring to 8 c.c. If this amount 

 of acid is reached, and the pressure of the oxygen sufficiently dimi- 

 nished, which in a stoppered bottle is likewise brought about by 

 the presence of the lactococci, the lactobacilli can develop and cause 

 further souring. 



From the observation that by the described experiment more or 

 less perfectly anaerobic lactobacilli are obtained, follows that here 

 as in the case of Lactococcus different varieties may be expected. 

 At a continued research the differences prove to extend over other 

 characteristics also and may become so great, as well from a morpho- 

 logic as from a physiologic point of view, that it seems necessary 

 to create new species. 



Especially the dimensions of' the rods, the more or less branched 

 state of the colonies on agar plates, the slime formation, the either 

 or not originating of carbonic acid as fermentation gas beside (he 

 lactic acid, and the action or non action on different sugars give 

 rise to this consideration. The deeper however we enter into these 

 distinctions, (he more troublesome n becomes to devise such descrip- 

 tions as are wanted to present to other investigators an image of 

 the results of our own researches; so numerous become the forms 

 which nature, or better perhaps, which culture produces, and so 

 slight are the differences by which these forms are distinguished, 

 if we do not confine ourselves to the extremes of the groups. l ) 



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

 former occasion 1 named '-) Lactobacillus caucasicus and L. longus. 



l ) Kor further information sit \V. Henneberg, Zur Kenntniss der Milchsaure- 

 bakterien. Sonderabdruck aus Zsitschnft I'm Spintusindustns Nc 22-31, 1906 

 Parey, Berlin. 



-) Sur les ferments lactiques de l'industrie. Archives Néerlandaises. Sér. 2, T. (J, 



p. 212, 1901. 



