( 

 {publications 



OF THE 



"(University of Pennsylvania, 



Hew Serfea, Ho. 4* 



Contributions 



from 



The Laboratory of Hygiene. 



No. 1-2. 



The Biological Relation between Bacteria and the More 

 Highly Organized Flora of Running Streams. 



D. H. BERGEY, M. D. 



Comparative Studies upon the Pseudo-diphtheria, or 



Hofmann Bacillus, the Xerosis Bacillus, and the 



Loffler Bacillus. 



D. H. BERGEY, M. D. 



PUBLISHED FOR THE UNIVERSITY OF PENNSYLVANIA. 



PHILADELPHIA. 



1898. 



