105 



183 



(as in the case of the club-shaped strain shown in tlio jjholo). "S east extract is uadoubtledly 

 the best source of nitrogen, and with this, we weie able, in tiie case of the two strains 

 shown in the table, to study its relations to the different sugars. Of these strains, No. 11 

 (the strain from infant III, PI. LI) is highly forked whereas No. 12 is only very slightly 

 irregular. They behave towards the sugars (Table XXXII) as Bbni. breve and Bbm. lonyum 

 respectively, and thus probably represent different species. Haclcriuin bi/iduin has, however, 

 probably no connection with the betabacteria, and if it were not that We had previously 

 met with strains which, at any rate in a freshly isolated stale, formed great quantities 

 of by-products. We should hardly have reckoned Bad. bifidum among the true lactic acid 

 bacteria, as, though it does form some dextro-lactic acid, 30 — 40 % of the sugar fermented 

 is turned into acetic acid. Unfortunately, we did not succeed in preserving any of the 

 isolated strains long enough to enable us to observe whether the quantity of by-products 

 gradually decreased. 



The different species of Bad. bifidum doubtless constitute a separate genus, possibly 

 forming a connecting link between the lactic acid bacteria and the propionic acid bacteria 

 first isolated by Freudenreich and myself^). The rod forms coming under this head 

 can, as will be seen from the accompanying photographs (PI. LI), also be more or less 

 forked. We cannot here enter further into the qualities of the propionic acid bacteria, and 

 I must therefore refer to my Dairy Bacteriology. In Table XXXII will be found, by 

 way of example, details of two strains in their relation to the sugars, I would merely add 

 here, that these strains are also very strong fermenters of inosite. 



'j Landwirtschaftliches Jahrbuch der Schweiz. 1906, p. 320. 



I). K. n. Videnskab. Selsk. Skr., nalurvidensk- og matheni. Afd., 8 Række. V. ï. 



24 



