1889.] On a pure Fermentation of Mannite and Glycerin. 347 



Plates were again poured from a number of tliese fermenting solu- 

 tions of various ages, the resulting colonies were carefully examined 

 and again inoculated into the fermentable liquids, and it was only 

 when the purity and uniform character of the organism had thus 

 been fully established that the larger quantities of fermentable 

 material to be chemically examined afterwards were finally inoculated 

 as described below. , 



Microscopic Appearances. — Under high powers ( X 1000 X 1500) 

 the organism is seen to be a bacillus with rounded ends, occurring 

 chiefly in pairs, the individual bacilli vary in length from 1*5 /<, to 

 5*1 p., and in breadth, from 0"8 jn to I'O /t. Their appearance, however, 

 as is so frequently the case, varies considerably, according to the 

 medium from which they are taken. Thus in the fermenting liquids 

 they were often found to form long threads, whilst in gelatine and 

 other solid media they were usually found in pairs only. 



The accompanying figures, J^Tos. 1 and 2, illustrate the differences 

 io the appearance of the bacilli when taken from gelatine and 

 mannite-solution respectively. 



Fig. 1. Fig. 2. 



I ----- 



That this difference in appearance was not accidental but a constant 

 character of the organism was demonstrated by inoculating gelatine- 

 tubes from single colonies of the organism ; on microscopically ex- 

 amining the growths in these tubes, the characteristic short bacilli 

 were found, but no threads ; on inoculating, however, a series of 

 glucose-tubes from these gelatine cultivations, the long threads were 

 invariably found. 



Viewed in drop-cultivations, the bacilli were seen to be extremely 

 motile. 



Appearance in Gelatine- Tubes. — The growth is but little charac- 

 teristic ; in the depth the needle-track assumes a beaded appearance, 

 whilst the smooth surface-growth causes more or less rapid liquefac- 

 tion of the gelatine, according to the temperature and according to 

 the vitality of the organism ; thus at low temperatures or when the 

 organism has been inoculated from an old and exhausted previous 

 growth, the liquefaction is very slow. 



Appearance in Agar-Agar. — The organism forms an extremely thin 

 and almost invisible growth over the surface, which becomes hardly 

 more conspicuous even when incubated for some time. 



