viii Publications of the University of Pennsylvania. 



Mathematics 



T^o. I. 40 cents. 

 Contributions to the Geometry of the Triangle. By R. J. Aley. 

 Properties of the Locus r = Constant, in space of n Dimen- 

 sions. By Paul R. Heyl. 



Hygiene 



Nos. i-g. 40 cents. 

 The Biological Relation between Bacteria and the More Highly 

 Organized Flora of Running Streams. By David H. Bergey. 



Comparative Studies upon the Pseudo=diphtheria, or Hofmann 

 Bacillus, the Xerosis Bacillus, and the Loffler Bacillus. By 



David H. Bergey. 



History 



The Revolutionary Movement in Pennsylvania, 1760-1776, By 



Charles H. Lincoln. 



