196 SUMMARY OF CURRENT RESEARCHES RELATING TO 



M. roseus flavm grows well and is easily cultivated at room tem- 

 perature in broth and milk, and on all ordinary solid media except potato. 

 Gelatin is slowly liquefied. 



The coccus stains well, but is decolorised by Gram's method ; it is 

 nearly 1 fj. long and about 0*6^ broad. It is non-motile, aud divides 

 in only two planes (staphylococcus grouping). In the course of a month 

 or more milk showed traces of peptonisation without coagulation. The 

 tint of the pigment was estimated by means of the Bradley colour wheel 

 and Maxwell disks, the following percentage being obtained : red 72, 

 white 13, yellow 9, orange 6. 



Lactic Acid Bacteria and Cheese Ripening.* — Prof. R. Chodat and 

 N. 0. Hofman-Bang, who have devoted much attention to the question 

 of cheese ripening, have recently shown that the lactic acid bacteria 

 isolated from Emmentbal cheese are not able to dissolve the coagulated 

 casein. They therefore contest the statement of de Freudenreich, who 

 inclined to the view that lactic acid bacteria play the most important 

 part in the ripening of Emmentbal cheese. 



The authors, however, admit that they used casein which had been 

 washed and heated to 120°, and that it might be objected that the results 

 obtained from casein thus treated had only a relative value. 



The value of this objection, which might also be raised against ex- 

 periments made with sterilised milk, remains to be seen. 



Variability in Lactic Acid Bacteria in relation to their Fermen- 

 tative Power.f — The experiments of N. P. Schierbeck were intended 

 to ascertain whether the variation of fermentative power of microbes 

 in general, when retained through generations, could be excited experi- 

 mentally. For this purpose lactic acid bacilli were selected, since the 

 manifestation of fermentative power could be easily measured in terms 

 of the acidity produced in the medium. Experimentally, variation was 

 influenced by the addition of carbolic acid to the milk, and cultures 

 were obtained which excited fermentation in varying degree, and less 

 than that of the original culture. 



The impaired fermentative power was associated with a diminished 

 reproductive energy, and with increased resistance to extrinsic agents, 

 such as carbolic acid. These artificially produced cultures do not corre- 

 spond to those found in milk naturally and spontaneously coagulated. 

 Hence the formation of new races is only an apparent one, due to 

 extrinsic deleterious substances in the nutritive medium. 



Bacterial Flora of the Sydney Water Supply.}: — R. Greig Smith 

 has isolated from Sydney water the following new species and subspecies. 



Bacterium janthinum ii. subsp. n. — The main differences between 

 this subspecies and Zopf 's organism are the rapid liquefaction of the 

 gelatin (24 hours), the diffuse growth on agar, and the absence of an 

 alkaline reaction in milk. 



Bacterium album mesentericum sp. n. — A slender rod with rounded 

 ends, averaging 0-3 x 1*5 yu.. It is motile, is decolorised by Gram's 



* Ann. lnat. Pasteur, xv. (1901) pp. 36-48. 



t Kgl. Danske Widenskab. Selskabs Oversigt, 1900, pp. 113-37. 



t Proc. Linn. Soc. N.S.W., xxv. (1900) pp. 436-61. 



