Relative Suceptibility of Various Stocks of Mice to Experimental Disseminated Encephalomyelitis. ∗

Summary

1. The stock from which the host is taken is apparently important for the outcome of attempts to induce in mice experimental disseminated encephalomyelitis, for certain stocks of albino mice are susceptible and others, even though of related lines, are relatively resistant. 2. In 19% of the mice which reacted to homologous brain tissue-Freund type adjuvant mixtures, lesions characteristic of disseminated encephalomyelitis can be found in the central nervous system in the absence of any demonstrable objective symptoms of illness. 3. A diagnosis of the experimental encephalomyelitis should there-fore be based on the results of histological examination of the nervous system as well as on typical symptomatology. The question is discussed whether reactors might not have been overlooked among animals of other species hitherto employed, when the basis for the diagnosis of the encephalomyelitis was only the presence of outward signs of illness.