ECHOES OF BATS AND MEN 



In 1938, Donald R. Griffin, then a senior at Harvard, took a cage 

 of bats to the physics building, where one of the first laboratories 

 for detecting ultrasonic sounds had been set up. There, for the 

 first time, the high-pitched clicks by which bats navigate were 

 heard. This pioneer experiment has touched off ever-widening re- 

 search in physical biology, research which has included the investi- 

 gation of the navigating techniques of animals. Echoes oi Bats and 

 Men is a brilliant report on how studies of bats, porpoises, and 

 whirligig beetles and of electronic radar and sonar are now expand- 

 ing man's understanding of physics. Dr. Griffin shows how this 

 knowledge may be applied to help the blind "see." 



