612 the gum fermentation of sugar cane juice, 



The Vitality of the Spores. 



The spores of bacilli resist the action of moist heat at 100° C. 

 for some time, and the gum bacillus is no exception to this rule. 

 In testing how long they could withstand the action of boiling 

 water, several tubes of saccharose media were infected with 

 spores, and after attaching aerial condensers, the tubes were 

 immersed in brine, which was kept slowly boiling. The media 

 in the tubes boiled briskly. At intervals of |, |, 1, H, 2 J and 

 5 hours, tubes were taken out, cooled, and thereafter incubated 

 at 37°. In all cases growth occurred and gum was formed. The 

 spores can, therefore, withstand the action of boiling water for 

 at least five hours. 



According to Lafar, the potato bacillus can resist the influence 

 of. a current of steam for six hours, which marks it as being the 

 most powerfully resistant of all organisms hitherto observed. 

 The spores of the gum bacillus resist destruction as vigorously 

 as the potato bacilli, and, as we shall see, this is not to be 

 wondered at, for they have many points in common. 



The Varieties of the Organism. 



So far, with one exception, the; action of a bacillus w^iich was 

 separated from roller cane juice has been considered. In the 

 examination, however, of a number of raw and refined sugars, 

 many races of the same organism were isolated. A few of these 

 grew slowly, but otherwise they were identical with bacteria of 

 quicker growth. From the more or less extended examination 

 of some sixty bacteria, it became manifest that the races fell into 

 one, two, or three groups, according to the value placed upon 

 their growth characteristics. If they are divided into three 

 groups, the third of these (/3)8 of table) must be considered as 

 being derived from the second (/3), since upon repeated cultiva- 

 tion the characters alter and become identical with those of ^ 

 group. The j3 group differs from the a group chiefly in its 

 method of growth in gelatine. 



