The syndrome of lateral sclerosis has been a subject of contention among neurologists ever since Erb first described it. Actually the spastic paralysis which bears his name was in the beginning regarded as syphilitic, but that was long before the spirochete was thought of or the Bordet-Wassermann reaction discovered. Later opinion was divided as to whether lateral sclerosis was a special entity or part of another syndrome. All neurologists conceded the existence of a familial form, but some questioned the occurrence of the syndrome in the adult on a nonhereditary basis. Gowers1regarded the syndrome as a disease entity; so did Oppenheim2and Spiller;3Wilson4did not; we do. The reason why doubt has been cast on its existence is that lateral sclerosis may be the first, and for a long time remain the only, manifestation of what will later turn out to be multiple sclerosis,