A Sugar Bacterium. 



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j O 



Similar tubes placed in a vacuum also showed no growth beyond the 

 formation of the flocculent deposit, hardly slimy, and easily shaken 

 up into the clear supernatant liquid — a point of constrast of some 

 importance, for in successful cultures in cane-sugar the viscosity of the 

 liquid above is so great that it is very difficult to shake up the deposit, 

 which is also dense and gelatinous. 



Repetitions of these cultures gave the same results — a rapid develop- 

 ment of a very slight turbidity and formation of a small non-gelatin- 

 ous deposit which falls and leaves the liquid clear. 



Some attempts were made to see if varying the strengths and 

 composition of the levulose solutions would affect the matter — e.g., 

 Mayer's solution made with levulose gave little or no signs of growth 

 at all with the bacterium, though it proved a splendid medium for the 

 yeast. 



Curiously enough, a mixture of beet extract and this levulose- 

 Mayer's solution, though it encouraged abundant growth of the 

 bacillus, rapidly becoming turbid and then clearing as the deposit 

 fell, showed no viscosity nor was the deposit slimy, as occurs in beet 

 extract alone. 



Even made up with yeast-extract, no viscosity could be obtained : 

 nothing beyond the slight flocculence, and it was clear that levulose is 

 at best a poor food material for this bacillus. 



Mixed Sugar*. 



Proceeding from the observation that the bacterium undoubtedly 

 inverts saccharose, cultures were made as follows : — Dextrose-yeast- 

 extract and levulose-yeast-extract were mixed, and infected with the 

 bacterium : an excellent growth of the organism resulted, at both 

 32° and 24° C, but the deposit which resulted, consisted entirely of 

 the non-sheathed bacterium in flocculent masses, and it remains a 

 puzzle why the sheaths are formed in saccharose and not in the 

 two sugars resulting from its inversion. The only conclusion seems 

 to be that proportion of constituents has something to do with the 

 matter. 



' 1 Dextrin-Zi t eke i --Losu ng. ' ' 



Under the above . name, Grubler supplies a syrupy sugar in which 

 the microscope shows delicate needle crystals, and — merely in the 

 spirit of trying all experiments — this was tried with the following 

 results : — 



Made up with yeast water as a 10 per cent, or 15 per cent, solution, 

 the bacterium slowly formed a large slimy deposit in from five to ten 

 or twelve days at 15° and 23°, but not at 35°, in which rods and chains 

 existed in the colourless matrix. The rods measured 1'5/x x 1/x to 3/x x 1/z, 



