626 SUMMARY OF CURRENT RESEARCHES RELATING TO 



strains failed to demonstrate any distinction between Oriental and 

 American strains, the organisms exhibiting a remarkable agreement, 

 except with regard to the fermentation of glycerine. Two Manila 

 strains fermented in this medium ; the remainder of his Manila strains 

 and the whole of his New Orleans strains gave no reaction. Generally 

 speaking, dextrose, mannite and levulose were fermented regularly and 

 fairly strongly. Maltose, arabinose, galactose and salcin were also 

 fermented, but more irregularly, except under favourable conditions. 

 Dextrin, lactose, saccharose, raffinose, adonite, dulcite, amygdalin, inosite, 

 sorbite, nntrose and inulin were not changed in reaction. 



The types of media and the different sugars used had various effects, 

 some of them very definite and constant, on the amount of growth and 

 on the morphology of the organism. On dextrose, mannite and levulose, 

 in which media fermentation begins promptly, smears uniformly showed 

 much degeneration and involution. When, however, acid production 

 was delayed, degeneration and involution occur to a less extent. The 

 cultures on sugars not acidified give well-stained organisms, though 

 variation in morphology in different organisms is marked. Salicin 

 usually produces long, often thready, and at times almost filamentous, 

 organisms {B. proteiis type) not at all recognizable as B.pestis. Dextrin 

 and arabinous also show this tendency. Glycerin induces the formation 

 of short, chunky, deeply-staining bacteria, often showing the typical 

 bi-polar staining of B. pestis in exudates. 



Bacillus paralacticus." — B. paralacticus was isolated by F. 

 Duchilcek from lactobacilline. It produces in milk 0'6-0'7 p.c. lactic 

 acid, while B. hdi/aricus produces under the same conditions 2 • 3-2 • 5 p.c. 

 The whole amount of the fermented sugar in the milk is converted into 

 lactic acid. If the bacillus acts in the presence of the neutralized medium 

 (in the presence of calcium carbonate), 50 p.c. of the sugar can be 

 fermented in four months. Under the same conditions, B. bulgarims 

 can cause fermentation of the whole of the sugar within ten to fourteen 

 days. The reason of this difference is that the coagulum produced in 

 the fermentation is sufficiently acid to inhibit the action of the former 

 species of bacillus. The best medium for the growth of B. paralacticus 

 is peptonized malt extract containing a suitable sugar. A further dis- 

 tinction between B. hulgaricus and B. paralacticus is that the latter 

 produces re-lactic acid, whereas the former proouces an inactive acid. 

 About 4*6 p.c. of the acid produced is in both cases acetic acid. 



Colour-changes produced by Two Groups of Bacteria on Casein- 

 ogen and certain Amino-acids.f — Elfrida C. V. Cornish and R. S. 

 Williams found that discoloured stilton cheese contains a large number 

 of organisms belonging to many different groups. Similar micro- 

 organisms are present in the milk from which the cheese is made, and 

 also in the water-supplies of the farms from which the milk is obtained. 



* Biochem. Zeitscbr., Ixxxii. (1917) pp. 31-47. See also Journ. Chem. Soc. 

 i. (1917) pp. G12-3. 



t Biochem. Journ., xi. (1917) pp. 180-7. See also Journ. Chem. Soc. i. (1917) 

 p. 613. 



