182 



/ 



104 



In milk, and especially in cheese, we encounter some small GnAM-positive rods. 

 Which entirely resemble Mbm. laclicum, and can, like the latter, stand heating to 80°, 

 and only grow in the upper part of the agar tube. In stab cultures, the surface growth is 

 a faint yellowish-green, which it can also be, at times, in Mbm. ladicum. They form, 

 however, too little acid to be included among the lactic acid bacteria. They curdle milk 

 in the course of a Week without altering the reaction to any considerable degree, and 

 they dissolve the casein gradually. In milk to which chalk has been added, some few 

 strains can form up to 80 % SN, 54 % DN and 6 % AN. They therefore also liquefy 

 gelatin, especially that without sugar (AG). Dextrose gelatin on the other hand, will 

 not liquefy if closely sown, as the acid formed will impede the action of the proteolytic 

 enzymes. They split up hydroj^en peroxide, but do not reduce nitrates. We will for the 

 present call this bacterium Microbaderium liquefaciens (PI. L). It is possible, however, 

 that it may belong to quite another place in the system. 



Bacterium bifidum {Bacillus bifidus). 



At the commencement of the century, Tissier^) made the discovery that the over- 

 whelming majority of the bacteria in the fæces of breast children did not consist, as with 

 adults, of CiRAM-negative coli bacteria, but of a GnAM-positive, irregular rod form, which 

 could be club-shaped, or even forked, wherefore he termed it Bacillus bifidus (PI. LI). 

 As the bacterium does not form spores, it will be correct to alter the name to Badeiium 

 bifidum. It is immotile, obligatorily anaerobic, and requires sugar for its development. 

 It forms an acid not precisely defined, but no gas. Casein and gall appear, strangely 

 enough, to impede its growth. It grows for the most part so slowly, that even at the optimal 

 temperature, 37°, it may often take a whole week before the colonies become visible. 

 It is killed by heating to 60°, can still grow at ordinary indoor temperature, and at 

 40°, albeit extremely slowly. According to Tissier's investigations, it is said not to be 

 quite so predominant in the fæces of infants reared from the bottle. 



We have also investigated a great number of fæces samples both from healthy breast- 

 reared children and healthy bottle-fed infants, the material being procured, partly from 

 private acquaintances, partly through the courtesy of Professor Leopold Meyer, from 

 the Lying-in Hospital. The direct microscopic examination revealed, besides a quantity 

 of more or less GRAM-positive cocci^), on the whole not more GRAM-positive than Gram- 

 negative rods. No constant dilîerence in the flora of fæces from breast childern and 

 fæces of bottle-fed children could be discerned. 



It was very difficult to isolate the GRAM-positive rods, and when we tiiially succeeded, 

 they perished so rapidly that as a rule wc had not time to investigate them further. We 

 Were never able to keep a strain alire for more than a year. Strains which could be further 

 inoculated from one anaerobic agar tube (high tubes, from which the oxygen of the air 

 was excluded by means of pyrogallate of potassium, according to Striuolt's method) 

 to another, often refused to grow in freshly sterilised liquids covered with lluid paraffin 



') Recherches sur la flore intestinale des nourrisons. Paris 1900. 



In a single instance, we found only streptococci in the fæces of a breast child. It was stated 

 that both nurse and child were healthy. 



