In previous reports (1, 2) a description was given of abnormal gait and degeneration in the nervous system which developed in pigs under certain experimental conditions. It was suggested that these effects were the result of a dietary deficiency and evidence was presented which indicated that the changes took place in spite of adequate amounts of vitamin A, thiamin, riboflavin, nicotinic acid or vitamin E. Inanition or mineral deficiency did not seem to play any role. It was shown that a nerve-protecting factor was present in liver and, to a lesser extent, in yeast.In an attempt to discover the nature of this protective factor or factors, further experiments have been carried out in which the basal deficient diet has been supplemented by various crude sources of accessory factors, chiefly various fractions of liver. More recently the newer vitamins, pyridoxine, pantothenic acid and choline have been used in conjunction with thiamin, riboflavin and nicotinic acid. It is the purpose of this report to give an account of the observations dealing with crude substances. Particular interest attaches to the nerve-protecting value of different fractions of liver, for degeneration similar to that observed in the pigs occurs in many cases of pernicious anemia in man. The fractions of liver used were those I

No abstract