The President of the United States of America, authorized by Act of Congress July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Colonel (Medical Corps) William Holland Wilmer, United States Army Air Service, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I. As Surgeon in charge of Medical Research Laboratories, Air Service, American Expeditionary Forces, since September 1918, Colonel Wilmer has rendered most distinguished service. His thorough knowledge of the psychology of flying officers and the expert tests applied efficiently and intelligently under his direction have done much to decrease the number of accidents at the flying schools in France and have established standards and furnished indications which will be of inestimable value in all future work to determine the qualifications of pilots and observers. The data collected by him is an evidence of his ability, his painstaking care, and of his thorough qualifications for the important work entrusted to him. The new methods, instruments, and appliances devised under his direction for testing candidates for pilots and observers have attracted the attention and been subject of enthusiastic comment by officers of the allied services, and will be of great importance in promoting the safety and more rapid development of aerial navigation.