& ae 2 | 
- rials 
ae PHILIP P. CALVERT, Ph.D., Editor. 
gees E. T. CRESSON, Jr., Associate Editor. 
ee 2 HENRY SKINNER, M:D., Sc.D., Editor Emeritus. 
SL eee ADVISORY COMMITTEE: 
ete Muay  £ZRA\T, -CRESSON: J. A. G. REHN, 
Sp PHILIP LAURENT. : ERICH DAECKE. H. W. WENZEL. 
a. PHILADELPHIA: 
THE ACADEMY OF NATURAL SCIENCES, 
pes eed LOGAN SQUARE. 
Entered at the Philadelphia Post-Office as Second-Class Matter. 
PROPE RTY 
