494 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



do not multiply by division, and consequently cannot be micrococci. 

 The author several times observed them develope into short rods, 

 their refrangibility at the same time diminishing ; they display great 

 resistance to desiccation from their distinct gelatinous investment. 

 He concludes that they must, for these reasons, be regarded as resting- 

 forms or arthrospores, corresponding to those already described by 

 van Ermengem and Doyen. 



Dr. Hiippe maintains that the " genera " of spiral bacteria cannot 

 be distinguished by the character and arrangement of the coils, since 

 these are subject to great variation, but by the mode of production of 

 the spores. Those he calls vibrios, which, like Vibrio rugula, form 

 endogenous spores with distinct broadening of the cell ; spirilla, those 

 which form endogenous spores without any broadening of the cell ; 

 and spirochaetse, those which do not produce endogenous spores, but 

 arthrospores. 



Abscess-producing Diplococcus.* — Dr. E. Bumm describes a 

 microbe found in an abscess in the mamma, and which was apparently 

 the cause of the inflammation, It differs from Eosenbach's Staphylo- 

 coccus pyogenes aureus in being a true diplococcus, consisting of two 

 hemispherical halves separated by a thin slit, but kept together by a 

 common envelope, and in not having the golden-yellow colour of that 

 microbe. By infection with the microbe reproduced by pure culture, 

 abscesses were induced in rabbits. Its pathogenic properties were 

 proved also in other ways. 



Bacterium of Panic Fermentation.f — According to M. E. Laurent 

 the principal agent in the fermentation of bread is a microbe which 

 he calls Bacillus panificans. It may easily be obtained by taking 

 leaven from the flour of wheat, rye, or spelt, and mixing it with a 

 small quantity of sterilized water, and then using as the nutrient 

 material Koch's gelatine acid or slightly alkaline. At the end of the 

 second or beginning of the third day, the characteristic colonies are 

 seen, of circular outline with entire margin. In reflected light they 

 are a very pale chrome-yellow, by transmitted light of a brownish- 

 grey tint, more or less marked at the end of some days. The develop- 

 ment of the colonies is very slow, and they scarcely ever touch one 

 another. At the ordinary temperature, 15° C, they do not liquefy 

 gelatine. By these characters B. panificans is easily recognized in a 

 mixture of other bacteria of putrefaction. Development takes place 

 between 6° and 45°, the optimum temperature being from 33° to 34° C. 

 In the first days of the culture very short and motile rods are seen ; 

 later, when the liquid becomes poorer, only elongated bacilli, some- 

 times very long filaments. 



The spores of B. panificans are killed only by a temperature of 

 100° C. prolonged for ten minutes ; the rods without spores resist 

 even a higher temperature. It renders the gluten of paste readily 

 soluble, and developes at the expense of cooked starch in a medium 



* SB. Phys.-med. Gesell. Wiirzburg, 1885, pp. 1-7. 



t Bull. Acad. Koy. Sci. Belgique, x. (1885) pp. 765-75. Cf. this Journal, iv. 

 (1883) pp. 690, 885. 



