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A. Section of normal cerebellum of a dog. B. Section of cerebellum of a dog after 

 injection of diphtheria toxin. C. Section of cerebsllum of a dog after injection <>f 

 diphtheria toxin plus morphin. D. Section of cerebellum of a dog after injection of 

 diphtheria toxin and the continuous administration of nitrous oxid for four hours. 



FIG. 74. PROTECTIVE EFFECT OF MORPHIN AND OF NITROUS OXID ON THK BKAIN- 

 CELL8 OF DOGS WHICH HAD RECEIVED INJECTION OF DlPHTHKKIA Tnxi.V. 



Compare the Purkinje cells in C and D with the disintegrated hypochromatic cells in 

 B. (From photomicrographs, X 310.) 



