296 



for far the greater part of common colibacteria 1 ), among which there occur real 

 lactic acid ferments, but as in the case described before in quite an inferior 

 number. This fact acquires a special significance when we consider that Escherich, 

 the discoverer of the colibacillus, has proved that this condition exists directly 

 behind the baby's stomach, where colt and aerogenes are predominant which, in 

 reference to the preceding, necessitates the conclusion that even at those portions 

 of the intestines where a lactic acid flora should first be looked for, it is evi- 

 dently unable to sustain itself. 



There is no doubt but here too, the strongly disinfecting action of the 

 stomachal hydrochloric acid plays a part, as this acid, at a much lower titer than 

 the lactic acid checks the growth of the lactic acid ferments, but hence can be 

 neutralised by much less alcali, which is not indifferent to colt, which produces 

 alcali. 



In so far as the theory of Metchnikoff and Combe is right, after which 

 yoghurt or other sour milk preparations counteract the auto-intoxication from the 

 intestinal canal, it seems certain that here should more be thought of the in- 

 fluence of a milk diet and the free acid taken up with the milk, than of a specific 

 intestinal flora. But in how far the apparently proved decrease of indol and 

 phenol, whose quantity is considered a determining the degree of auto-intoxication, 

 deviates, at a nutrition with soured milk preparations instead of meat, from this 

 decrease when non-soured milk is used, - to my opinion the real core of the 

 question, has not been considered by the said authors. 



Admitting that the soured preparations really deserve to be preferred, I 

 think that especially in Holland, it must be possible with good buttermilk in as 

 simple a way to reach the wished for end, as with the various exotic ferments, 

 whose descriptions give the impression that the preparators are but imperfectly 

 acquainted with the general phenomena of the lactic acid fermentation in milk. 



Although I see no fundamental difference between the use of buttermilk and 

 yoghurt, it is certain that the latter may be prepared in a very simple way under 

 medical control, and hence, to my meaning, deserves to be recommended in 

 certain cases. 



Summarising the preceding I come to the following conclusion. 



In milk three chief forms of lactic acid fermentation, determined by tempe- 

 rature, are to be distinguished, namely at very low temperature, the slimy lactic 

 acid fermentation; at a middle temperature the common lactic acid fermentation 

 caused by Lactococcus ; and at higher temperature the lactic acid fermentation by 

 Lactobacillus. 



The elective culture of the microbes of the slimy fermentation succeeds by 

 cultivating baker's yeast in absence of air between 15 and 18 C. in malt extract 

 and transferring to boiled milk or whey at as somewhat higher temperature. The 

 acidity obtained remains low and amounts to 3 to 5 c.c. of normal acid per 

 100 c.c. of milk. 



*) For different children not always the same varieties; sometimes, for instance 

 non-fermenting forms reminding of Lactobacillus, for which I before indeed took such 

 bacteria. 



