SEP 18 ?gn 



TRANSACTIONS OF THE 

 WAGNER FREE INSTITUTE 



OF SCIENCE 

 OF PHILADELPHIA 



of 



! UNI. 

 \ or 



VOLUME VI1-PART 2 

 JULY, 1913 



WAGNER FREE INSTITUTE OF SCIENCE 



MONTGOMERY AYE. AND SEVENTEENTH ST. 



PHILADELPHIA 



