636 SUMMARY OF CUEEENT RESEAECHES RELATING TO 



rabbits immunised against B. paratyphosus A Brion and B. Gaertner 



did not agglutinate the bacillus under consideration. 



Jelly-forming Bacteria.* — M. Gronnermann describes several jelly- 

 forming bacteria. (1) Myxobacterium Beta, met with in jelly-like 

 masses during the manufacture of sugar. It forms slender non-motile 

 rods 2-5/i long, 0" 3ft thick, two or more being often joined together; 

 it stains by the ordinary anilin dyes, showing a granular appearance, 

 but no distinct capsule ; growth is slow at room temperature, and best 

 at 34-37° C. ; it ferments sugar only slightly, and without acid forma- 

 tion ; at room temperature, or at 37° C. after 24 hours, it forms oval 

 spores with cross sections wider than the bacilli, but this is preceded by 

 the formation of threads which break up into short rods, each of which 

 forms a spore. 



(2) Plennobacterium Gon. appears as a transparent expansion of a 

 fine thready slimy consistence on agar-plates exposed to the air of the 

 room of the sugar press. Morphologically the organism resembles the 

 hay bacillus. Individual rods are 2'5-bfi long and 0'4-0'6/x, wide, 

 and have either blunt or, more often, finely pointed ends ; the threads 

 are often much tangled ; growth is slower at room temperature than the 

 Myzobacterium ; spores are formed at 37° C. after 24 hours. 



Dicyandiamid-bacteria.+ — R. Perotti finds that in nutrient liquids 

 containing a suitable amount of glucose, and for nitrogenous material 

 only about 1-2 p.c. of dicyanamide, there occurs a vigorous and charac- 

 teristic development of micro-organisms. These belong to different 

 bacterial forms and classes, many not yet described, some being ordinary 

 soil organisms, but only certain of these microbes find in this medium 

 the best conditions for development. The dicyanamide is incapable of 

 undergoing a fermentative action. 



Lactic Fermentation in Milk.J — M. W. Beijerinck finds that from 

 a temperature point of view there are three classes of organisms in milk, 

 viz. cryo- (5-20), meso- (20-35), and thermo-flora (35-45). The most 

 characteristic of the aerobic cryoflora are the different varieties of 

 Bacillus aromaticvs. It is possible to distinguish three forms of lactic 

 fermentation determined by the temperature ; a muciliaginous fermenta- 

 tion at very low temperatures ; the ordinary fermentation by the Lacto- 

 coccus at medium temperatures ; and at a relatively high temperature the 

 fermentation by the lacto bacilli's. Cultures of the mucilaginous lactic 

 fermentation thrive in cultivations of baker's yeast, anaerobically. at 

 15-18° C. in malt-extract, and in boiled milk or skimmed milk (petit 

 lait) at 25-30° C. The acidity of the fermentation is low. Cultures of 

 Lactococcits lactis are obtained by allowing milk to become sour in a 

 closed flask at 20-25° C, and sub-culturing in boiled milk at the same 

 temperature. The acidity is about 8 c.mm. of normal acid to 100 c.mm. 

 of milk. Cultures of lacto bacillus are best obtained in butter-milk kept 

 anaerobically at 37-40° C, and sub-cultured into boiled milk at over 

 30° C. The degree of acidity may reach 18-23 c.mm. of normal acid to 

 100 c.mm. of milk. 



* Centralbl. Bakt., 2te Abt., xxi. (1908) p. 258. t Tom. cit., p. 200. 



X Arch. Neerland. Sci. Exact, et Naturel., xiii. (1908) p. 357. 



