34'2 



DISEASES OF UNCERTAIN ETIOLOGY 



Longitudinal section of jiopliteal nevve from a case of acute beriberi. VVeigerl-l'al stain, 

 showing different degrees of degeneration of the medullary sheath. (P'rom Ilcrzog, plate lent 

 through the courtesy of 7/ie Philippine Journal of Science.) 



Fibre from sciatic nerve of fowl suffering from polyneuritis (Marchi method), showing 

 advanced degeneration. (From Vedder and Clark, and plate lent through the courtesy 

 of The Philippine potirnal of Science.) 



