Transactions of the 
ACADEMY of SCIENCE 
af Sa in t L oO wis 
VOLUME XXIX, No. 6 
Some Problems of the 
Middle Mississippi River Region 
During Pleistocene Time 
og 
PercivaL ROBERTSON 
A condensation of 
“ a dissertation presented to the Board of 
Graduate Studies of 
Washington University in partial fulfillment 
Of the requirements for the Degree of Doctor of philosophy, 1936. 
Issued July 30, 1938 
