76 B. BRADLEY. 



the Gaertner type, have been in the past classified in that 

 group. 



It would be advantageous if some common name were 

 definitely agreed upon to describe the organisms now under 

 discussion. Even the above triple title does not truly 

 include all members of the category to be dealt with. As 

 Gaertner was the first to describe an organism of this 

 group, I will, in the rest of this paper, as I have upon pre- 

 vious occasions, (1) use the term " Gaertner Group" (or 

 "Type") as a collective expression to describe bacilli of 

 this order including b. paratyphosus, b. enteritidis of food 

 poisoning, b. danysz (rat virus), b. icteroides, and b. hog 

 cholera. 



Organisms of the Gaertner group are fairly widely dis- 

 tributed in nature especially in association with certain 

 pathological conditions in men and animals. That first 

 found was isolated by Gaertner (2; from the flesh of a cow, 

 eating of which had caused fifty-three cases of gastro- 

 enteritis, with one death. Thereafter similar organisms 

 have been detected, not only in a great number of food- 

 poisoning epidemics, but in numerous other situations 

 presently to be referred to. Nowadays it is recognised 

 that there exists a group of bacilli morphologically similar 

 to the bacillus typhosus (Bberth Gaffky), which have, how- 

 ever, many of the characteristics of bacillus coli communis, 

 but which can be sharply enough separated from either of 

 these, and which in themselves form a well-defined group 

 allied by a number of characteristic properties, even if 

 showing amongst themselves certain differences. Since 

 the discovery of the first member of the group, they have 

 been isolated from an ever- widening range of sources. 



History of the Gaertner Group. 

 It is not my intention here to go fully into the past 

 history of the Gaertner group, or to attempt to give a 



