SUSCEPTIBILITY OF AMPHIBIAN OVA TO X-RAYS 



477 



TABLE 6— Continued 

 Experiment Al 



Small blastopore at time of exposure. All appeared to 

 develop normally although not all were followed through 

 metamorphosis. 



z a 

 m % 



Hours 



161 

 171 

 18} 



20f 



21} 45 



22} 45 



45 



23i 



26 



33} 



45 

 45 

 45 



Min 



45 60 

 45 

 45 

 45 



Experiment B 



Results 



-3 



■a o 



13 



a 8 

 Q r 



0) 



> 



I 

 o 



03 



j3 .n>^ (u ft o H 



Per^ Per' Per\ Per Per Per 

 cent cent cent cent cent cent 



1.7 



.3 65 30 

 36.2 63.81 



|36.7 

 39.4 



12.5 



18.2 



87.5 



5.9 



75.8 0.6 

 83.3 16.7 

 87.5 12.5 

 58.8 35.3 



1.5 



100 



Remarks 



Development retarded. None lived beyond 8th day. 

 Development retarded. None lived beyond 8th day. 

 Development retarded. None lived beyond 8th day. 



Only one specimen lived beyond the 9th day. This specimen 

 metamorphosed . 



Backward in development. All dead one week after irradia- 

 tion. 



Backward In development. 



Backward In development. 



Backward In development. 



Backward in development. 



Development apparently normal in all specimens 

 not all were followed through metamorphosis. 



None lived more than two weeks. 

 None lived more than two weeks. 

 None lived more than two weeks. 

 None lived more than two weeks, 

 though 



Experiment C 



The percentage In the last column Indic ates the number alive 

 two weeks after fertilization. Gastruiation was well ad- 

 vanced 23 hours after fertilization. 



Experiment D 



Percentage in last column as in Experiment C. Gastruiation 

 visible In 19th hour and nearly complete in 25th hour in 

 most specimens. 



