(a) 



'■'7i 



«iB 



(b) 



^, 





1i 



s^^^ti»- ._V^.^J*l.-„ ...m 



*, 



Fig. 3. Mouse bone-marrow, (a) Undifferentiated small round cell 6 hours after whole-body 

 X-irradiation with 1.000 r: partial nuclear pycnosis (NP), widening of the perinuclear space 

 (x) and marked swelling and/or disruption of mitochondria (M). X 30,000. 



(b) Myelocyte 24 hours after whole-body X-irradiation with 600 r. Asymmetrical partition 

 of a centriole ( j ). X 47.000. 



