Smithsonian Report. 1962. — Christenaon 



Plate 6 



Fruit-fl\' pupae are exposed to gamma radiation inside tlie sealed lead cask. Adults emerg- 

 ing from treated pupae are sterile. (Photo by R. Wenkam, Konolulu.) 



In fruit-fly radiation sterilization experiments, sterile ily pupae are placed in small aerated 

 boxes with honey water for food. After all flies hav'c emerged a few days later, the boxes 

 are distributed over the experimental area with an airplane. (Official photograph, 

 U.S. Navy.) 



