PORTO RICO AGRICULTURAL EXPERIMENT STATION, 
D. W. MAY, Agronomist in Charge, 
Mayaguez, P. R. 
BULLETIN No. 25. 
Under the supervision of the STATES RELATIONS SERVICE, 
Office of Experiment Stations, U. S. Department of Agriculture. 
THE BAT GUANOS OF PORTO RICO 
AND 
THEIR FERTILIZING VALUE. 
BY 
P. L. GILE, Chemist, 
and 
J. O. CARRERO, Assistant Chemist. 
T 
Published July 8, 1918 
WASHINGTON: 
GOVERNMENT PRINTING OFFICE. 
1918. 
