618 THE GUM FERMENTATION OF SUGAR CANE JUICE, 



film. Group /3/3 : The bouillon becomes turbid and forms a white 

 sediment and a very slight surface-ring. Indol is formed by all 

 the groups, and nitrate may be slightly reduced to nitrite. 



Milk. — AW groups coagulate and then slowly peptonise the 

 casein, but group a is much slower in its action. The reaction of 

 the supernatant liquid may be faintly acid (o), amphoteric (/3/3), 

 or alkaline (|3). 



Peptone- saccharose fluid. — The white, milk-like appearance is 

 very characteristic. 



Potato. — Group a : There is formed a reddish-white thin layer 

 upon a reddish ground. The thin layer becomes folded into small 

 delicate wrinkles. Sometimes in place of wrinkles drops of a 

 white water}^ fluid exude from spots scattered over the apparently 

 red surface of the potato. Group (i : The cultures are of various 

 shades of stone, yellow or yellowish-brown. They are raised and 

 undulating and soon (3-4 da3^s) become coarsely wrinkled. Group 

 ^^ : The growths are similar to /3, but in addition the medium is 

 frequently darkened in the vicinity of the culture. 



Temperature. — The organism grows at 15°, 22°, 30°, and most 

 quickly at 37°; above 37° the growth rapidly diminishes; with 

 the exception of the cultures in gelatine, which were made at 22°, 

 the descriptions of the growth characters applj^to cultures at 37°. 



The Gum-forming Bacilli previously Described. 



From the literature at my disposal upon this subject I have 

 found notes upon a number of sporeless bacteria capable of con- 

 verting saccharose into gummy substances when natural media, 

 such as slices of beet, were infected. As, however, the organism 

 separated by me is a spore-forming bacillus, mention of other 

 spore-bearing organisms which are known to form gum from 

 saccharose need only be made. 



Fritz Glaser* separated an actively motile short rod-shaped 

 bacterium, Bact. gelatinosum hetoi, from beet juice that had 

 undergone a mucinous fermentation. It rapidly liquefies gelatine, 

 produces gas w^hen grown in beet juice at 40-45° C, and is not 



* Fritz Glaser, Cent. f. -Bakt., 2te Abt., i. 879. 



