THE RELATIVE PHYSIOLOGICAL EFFECTS OF β- AND γ-RAYS UPON THE EGG OF NEREIS

When Nereis eggs are exposed to radiations from a tube of radium emanation, the walls of which absorb all the α-rays, the resulting physiological change is produced by rays having a coefficient of absorption of the order of 23.9 cm.(–1) This fact indicates that the physiological effect is due almost exclusively to β-rays. The γ-rays alone can produce the reaction. To produce equivalent physiological effects exposure to γ-rays alone must be approximately 60 times as long as exposure to β- and γ-rays together.