BACILLI OF THE COLON-TYPHOID-DYSENTERY GROUP 719 



No. IV agglutinated in the Flcxner serum, but not at all with typhoid 

 serum. 



It would be confusing to go more deeply into the Morgan group. 

 It is important, however, to mention them since his work illustrates 

 the possibility of there being a large number of insufficiently differ- 

 entiated types of Gram-negative bacilli in the intestines of human 

 beings. In view of the many researches of recent years in which 

 the possibility of variants of unknown species in regard to sugar 

 fermentations, agglutlnability, etc., has been pointed out, it would 

 seem proper to advise great caution in accepting as new species, 

 organisms which differ from well-known types in only one or another 

 characteristic. 



