LESIONS OF THE NERVOUS SYSTEM IN VITAMIN DEFI- CIENCY I. RATS ON A DIET Low IN VITAMIN

Lesions of the peripheral nervous system have been recognized and described in animals fed diets deficient in the antineuritic vitamin B, but there has been relatively little written about nervous system lesions in association with diets deficient in vitamin A. Hart , Miller and McCollum (1) described histologic changes "not unlike those recorded for beri-beri" in the nervous system of swine fed certain wheat and grain mixtures, and they concluded that these changes were the result of toxic materials in the food rather than due to the absence of vitamin A. Steenbock, Nelson and Hart (2) described unsteadiness of gait in a dog fed a diet deficient in fat-soluble vitamin but made no mention of examination of the tissues of the nervous system. Mellanby (3--5) observed incoordination, spasticity and weakness in young puppies fed a diet of 10 per cent wheat germ which was at the same time deficient in fat-soluble vitamins. He described lesions consisting of scattered degeneration in the spinal cord and observed that the ascending fibers were particularly involved. He related these lesions to a positive harmful influence in the wheat germ in the absence of a defending chemical substance like vitamin A. More recently Suzman, Muller and Ungley (7) have described experiments in which adult dogs were fed a diet abundant in cereal and lacking in vitamin A conducted with the idea of attempting to produce lesions in the spinal cord, but they did not succeed in accomplishing this end.