Contents

22 July 1966
Vol 153, Issue 3734

About The Cover

Diaphragm tissue fixed in glutaldehyde and osmium and embedded in epon. The accidental crystallization of the stain, uranyl acetate, resulted in this esthetic artifact (about X 1700).[Carl Zeiss, Inc.; O.James Inashima, College of Pharmacy, Northeastern University, Boston, Massachusetts]