Fio. 72. — Showing effects of 

 rays of radium upon plants. 

 (From Gager.) The plants in 

 this case are Oiiagra biennis, 

 showing arrested development. 

 The ovary was exposed to 

 radiations of radium bromide 

 (lOjOooX) in a sealed glass 

 tube for 53 hours. 



