A Note on the Inter-classification of the Gaertner Group.

THE bacteria which may be included together as the Gaertner Group are of considerable imnportance, comprising as they do most of the bacteria fotund in outbreaks of food poisoning and in paratyphoid fever, while they are etiologically concerned with a number of diseases in aninmals both domesticated and wild. The arrangement of bacteria into groups is very convenient and has been extensively practised. The Gaertner group itself is really a subgroup of the large coli-typhoid group, the members standing in their cultural characters between the chemically active coli grouip and the chemically rather inactive typhoid group. The differentiating characters of the Gaertner group are chiefly cultural and may be stated as follows: Short sporeless bacilli with rounded ends usually exhibiting marked motility. Grow as a white or translucent growth upon gelatine without any liquefaction. Produce at first some acid in litmus milk, then after a few days (the exact time shows considerable variation) marked production of alkali. The milk is never clotted. Indol is not produced. Glucose and mannite are fermented with production of acid and gas, while lactose and saccharose are not fermented. The bacilli found in nature with these cliaracters may be conveniently divided into two sub-groups: Sub-group A. True Gaertner bacilli. B. Para-gaertner bacilli. True Gaertner bacilli. These bacilli are all culturally indistinguiishable, and in addition to the above group characters they ferment dulcite,