Contents

08 July 1966
Vol 153, Issue 3732

About The Cover

A Mexican freetail bat (Tadaridabrasiliensis mexicana as it emerges from Carlsbad Caverns at dusk. The camera was timed by a signal form a photomultiplier tube when the bat intercepted a beam of light. See page 201. [Harold E. Edgerton, Massachusetts Institute of Technology]