412 A MANUAL OF BACTERIOLOGY 



Group II contains the forms which ferment hexoses, man- 

 nitol, and either xylose or arabinose, but rarely both, 

 with acid-formation only, no gas. The arabinose- 

 positive forms correspond to the Flexner-Y group of 

 dysentery bacilli, and the arabinose-negative forms to 

 B. typTiosus. 



Group III contains forms which ferment glucose and other 

 hexoses, with gas formation. They also ferment mari- 

 nitol, rhamnose and 'arabinose, but not xylose, and 

 usually not dulcitol. Milk is first acidified, but in from 

 five days to six weeks becomes alkaline. This group 

 includes B. paratyphosus A and B. pullorum, the cause 

 of white diarrhoea of chicken. (Para A may or may not 

 ferment dulcitol.) 



Group IV contains forms which ferment xylose, rhamnose, 

 and generally dulcitol, usually with gas formation ; 

 some ferment arabinose as well. They all produce a 

 rather prompt alkalinity in milk. This group includes 

 B. paratyphosus B (termed B. schottmulleri), B. sui- 

 pestifer, B. enteritidis, and Klein's B. gallinarum of 

 fowl typhoid. Morgan's bacillus (see p. 445 ; termed 

 B. morgani) is provisionally placed in this group, though 

 its true position is obscure, as it forms gas from hexoses 

 only. By its limited fermentive power it is allied to 

 B. shigce, by its indole production to Flexner's bacillus, 

 and by its gas production to the paratyphoids. 



The lactose -ferm enters are divided into two groups : 



Group V is distinguished from all the previous groups by its 

 members fermenting lactose, and frequently salicin, 

 dulcitol, sucrose, raifinose and glycerol, with a strong 

 acid reaction and moderate quantity of gas composed 

 of equal volumes of C0 2 and H 2 . Indole production 

 positive, Voges-Proskauer reaction negative. They 

 never liquefy gelatin and are not capsulated. 



B. coli is the type of this group, which also includes 

 B..neapolitanus and B. acidi lactici. 



Group VI differs from Group V in producing less acid and 

 more gas, which has the composition of two volumes of 



