ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 633 



M. Tissier in considering that the circumstances favourable to the 

 establishment of putrefaction, such as fermentation in an alkaline medium, 

 are also favourable to the production of a maximum number of spore- 

 forming micro-organisms. 



Micro-organisms of Cheese Making.* — P. Maze discusses the nature 

 and the comparative uses of the various micro-organisms occurring in 

 the manufacture of different kinds of cheese. He refers especially to 

 three varieties of Pemeillium, P. glaucum, P. candidum, and P. album ; 

 this last occurs in the refined cheeses, and is most important from its 

 property of destroying lactic acid and lactose, and may be regarded as an 

 obligate intermediary between the lactic fermentation necessary to the 

 cheese making, and the casein ferment indispensable to the refining 

 process, since the casein ferments cannot develop in the presence of 

 acids ; the characteristic flavour of Brie and Camembert cheeses being 

 due to this mould ; it is apparently of use in obviating the drying of the 

 surface, and in maintaining the porosity of the cheese. 



Two Varieties of Vibrio aquatilis fluorescens.f — F. Fuhrmann 

 describes two varieties of fluorescent water vibrios : {a) was isolated 

 from surface water ; (b) was obtained from cistern water. 



(a) Grows well on nutrient gelatin at room temperature, forming 

 round, sharply contoured colonies, with denser central portions, and of 

 a faint yellow colour ; after a few days a green fluorescence is diffused 

 throughout the medium, which after a week remains unliquefied ; the 

 colonies are composed of long, slender, slightly curved rods, with 

 characteristic active vibrio movement ; they stain as well with aqueous 

 fuchsin as with gentian-violet solution, but not by Gram's method ; the 

 optimum temperature is 32° C, and when grown on agar at this 

 temperature the rods are shorter and stouter, and preparations show 

 3-5 polar flagella ; it forms a brown-yellow growth on potato, and 

 a light brown growth on white of egg, which, after two months, is 

 converted into an amber-brown transparent mass ; in nutrient broth 

 there is good growth, with the formation of a strong pellicle, but no 

 great tendency to thread formation ; in pepton-water there is not good 

 growth, and no pellicle is formed ; in a fermentation flask there is 

 clouding of glucose broth, but no production of gas. It grows best on 

 slightly alkaline medium (0 ■ 5 p.c. N) ; it grows in litmus milk, and 

 after five days at 22° C, it forms 2 p.c. N/10 acid. A dose of 15 mgrm. 

 was pathogenic for guinea-pigs when injected into the peritoneum ; white 

 mice and rabbits were unaffected. 



(b) Grows on nutrient gelatin as circular almost transparent colonies 

 cupped in the centre, and with delicate wavy margins ; the medium is 

 not liquefied ; fluorescence commences after 24 hours ; the colonies are 

 composed of closely arranged rods, which are slightly curved, about 

 1 " 5 jjl-2 fx long ; they stain like the first variety, and not by Gram's 

 method ; they are actively motile, and preparations made from agar 

 culture show 2-3 polar flagella ; the optimum temperature is 22° C. 

 On potato and on white of egg the growths are the same as with the 

 other variety ; in nutrient broth there is good growth at room tempera- 



* Ann. Inst. Pasteur, xsx. (1905) p. 378. 



t Centralbl. Bakt., 2 te Abt., xiv. (1905) p. 641. 



