238 EFFECTS OF EXPOSING GERM-CELLS TO RAYS OF RADIUM 



In the experiments here recorded the radium was used in the form 

 of radium bromide of strengths of 10,000 and 1,500,000 activity, in- 

 closed in sealed glass tubes, and also in the form of Lieber's radium- 

 coated rods of 25,000 activity. Thus, as previously described,* by 

 the use of the sealed glass tubes only the gamma rays and the more 

 penetrating of the beta rays were available, while in the case of the 



Fig. 67. Otiagra biennis. Functionally asymmetrical Rosette. The Pollen was 

 exposed for 21 Hours to Rays from Radium of 1,500,000 Activity contained in a 

 sealed Glass Tube. Ovary not exposed. Cf . figures 68, 69, and 70. 



coated rods the « rays could act. The method of treatment was to 

 tie the tube or rod so that it touched the ovary or anthers or both. 

 *Cf. p. Si. 



