IN our previous communications•,• two facts of acquired resistance to experimental allergic encephalomyelitis have been reported, namely,(a) after recovery from the conditions and (b) after immunization with a mixture of the non-encephalitogenic brain of an embryo or new-born rabbit with the adjuvant. Prior to our work, three other facts of induced resistance to experimental allergic encephalomyelitis have been described:(1) Ferraro and Cazullo• inoculated a mixture of monkey brain with paraffin oil and lanolin (without mycobacteria) in 15 daily doses to guinea pigs. On the fourth day after the last inoculation, the animals were troated with the encephalitogenic mixture. Out of 12 animals, 1 contracted t: he disease compared with 12 or 13 in the control.(2) Condie et al.• reported resistance in rabbits 45 days after immunization with homologous spinal cord.(3) Lumsden• reported resistance after inoculation with non-encephalitogenic mixtures of an alcohol extract of the brain or adrenals with the adjuvant and suggested that the resistance was called forth by the adjuvant.