Notwithstanding the wealth of contributions to knowledge of the pathologic picture and pathogenesis of multiple sclerosis, the status of these problems seems to be at present more confused than ever. Thus, aside from the classic form of multiple sclerosis, there are seriously considered acute, subacute, malignant and experimental forms, while some authors have included with this morbid condition disseminated encephalomyelitis, Schilder's disease, postvaccinal and postmeasles encephalitis, Binswanger's subcortical chronic encephalitis, neuroptic myelitis and what Bassoe and I1described as multiple degenerative softening. Another extreme is represented by authors, Spiller,2for instance, who described multiple sclerosis as merely a form of disseminated encephalomyelitis. The main reason for such confusion is the tendency to regard multiple sclerosis as a conglomeration of sclerotic plaques and to identify them with patches of so-called demyelinization. Since patches of demyelinated nerve fibers are present not only in multiple sclerosis but in many other diseases