In a paper written two years ago,1 I made a preliminary report on a number of cases of polyneuritis of obscure etiology and ventured the opinion that they were the result of unrecognized avitaminosis. I also discussed the relation of gastric and hepatic disturbances to the etiology of alcoholic polyneuritis; the rôle played by pernicious vomiting in the production of polyneuritis of pregnancy and of other types of polyneuritis; the effect of starvation in cachectic polyneuritis; the influence of gastro-intestinal and hepatic impairment in polyneuritis from arsenic and phosphorus poisoning; the part played in the occasional occurrence of diabetic "polyneuritis" by the exclusion of foodstuffs rich in vitamins, and the rare forms of neuritis in children suffering from severe gastro-intestinal disturbances. The conclusion was also reached that in polyneuritis, which has hitherto been regarded as due solely to specific causes, food deficiency or avitaminosis plays a definite, possibly ultimately