422 



CLEMENTE AND RICHARDSON 





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Fig. 6. (A.) Medium power view of the nucleus of the spinal tract of the trigeminal 

 nerve in same rat as 5D,E,F, sacrificed 3 months after irradiation with 10,000 rad 

 alpha particles. Note the widespread vascular hyalinization (arrows) and the absence 

 of normal-looking neuron cell bodies. Van Gieson's stain. X 360. (B.) Low power 

 view of 3 vessels in the white matter in the occipital corte.x of a cat 6 weeks after 

 irradiation with 10,000 rad alpha particles. X 250 (C and D.) Sections at the mid- 

 pontile le\-el in rat gi\en 12,500 rad alpha particles and sacrificed 10 days after radia- 

 tion. Note the frank hemorrhages (C) X 360, and the perivascular globules (arrows) 

 described by Brightman (1959) (D) X 560. 



