SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 92, NO. 3, PL. 3 



IRRADIATION 



TIME IN 



SECONDS 



TIME AFTER IRRADIATION 

 9 DAYS 



24- DAYS 



60 DAYS 



a 



6 



c 



2652 A 



3022 A 



EXPOsSrES OFlo^n'^i^°p-':ioj;:'c=^'-^"^^ ' ^"^ CHLORELLA VULGARIS AFTER 

 EXPOSURES OF 600 ^SECONDS AND 3600 SECONDS TO ULTRAVIOLET RAYS. 



.\o radiotoxicity was noted for the exposure of lOo seconds. 



