630 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tended ; the flagella could not be stained, and their position at one or 

 both ends of the organism could not therefore with certainty be deter- 

 mined ; the length of the spirillum varies up to 50 p., its breadth being 

 about y> fi. Since it is not coloured by bacterio-purpurin like the other 

 sulphur bacteria, he considers that this spirillum should be classed as an 

 independent variety. 



Bacillus macerus, an Acetone-forming Bacillus.* — F. Schardinger 

 found this organism as an accidental contamination in a potato medium 

 that had been sterilised for an hour on three successive days in a current 

 of steam, an unexpected fermentation occurring on incubating at 37° C. ; 

 he also found the bacillus in the mud of retting flax. The organism 

 appears as slender, actively motile rods 4 /x-Q /x long, • 8 /x.-l //. broad ; 

 when mature and in the sporing stage they are non-motile ; the spores 

 are situated at one end of the rod ; the ripe spores are oval, 2 /x long, 

 1 • 8 /t broad ; they are very resistant to the temperature of boiling water. 

 On nutrient gelatin plates with 3 p.c. dextrose, white pin-point colonies 

 appear after about 8 days ; in gelatin stab there is but feeble growth 

 in the track, no gas formation, no liquefaction of the medium ; on 

 sugar bouillon at 37° C. there is rapid and abundant growth, diffuse 

 clouding of the medium, and formation of a slimy deposit ; milk is 

 coagulated at 37° C. within 36-48 hours, the separated serum is clouded, 

 and there is abundant gas production ; on boiled potato at 37° C. there 

 is a vigorous moist shining growth, with copious gas production, which 

 after a few days gives off a pleasant fruity odour of acetone, the potato 

 becoming pappy ; microscopically the mass is seen to be rich in spores. 

 The author discusses the process of retting in various vegetables and 

 fruits, and gives details of the methods employed by him for obtaining 

 acetone from potato and other plants and fruits by means of this 

 organism, and for quantitatively estimating the acetone formed. 



Bacterial Rods of Pelomyxa Palustris.j — L. J. Veley describes 

 the bacterial nature of the rods of Pelomyxa Palustris as evidenced 

 by their motility, mode of division, their reaction, and culture. To 

 observe the motility the protozoon was crushed in a drop of water and the 

 bacteria being set free were watched continuously for periods of several 

 hours without removing the eye from the Microscope. The movement, 

 which was both horizontal and vertical, was at first active but became 

 sluggish, and later ceased ; the presence of a flagellum could not with 

 certainty be demonstrated. The division of the organism was observed 

 1 >y a similar method of continuous watching ; on several occasions single 

 rods were seen to become constricted, forming two equal joints, one of 

 these again becoming constricted and so forming a three-jointed rod, 

 and so on till a six-jointed rod was produced, when separation occurred 

 by breaking into two ; but in no instance was a single unit set free. 

 The rods stained well with all bacterial stains and by Gram's method. 

 After several attempts, an approximately pure culture was obtained on 

 fresh sheep's serum ; the culture showed motile, two-jointed rods : later 

 filaments were formed, and "pseudo-branching" of these was also noted. 



* Centralbl. Bakt., 2 te Abt., xiv. (1905) p. 772. 

 t Journ. Linn. Soc, xxix. (1905) p. 374. 



