RESUMO
1- During the past three years 35 experiments in inoculation with Mycobacterium leprae were undertaken on approximately 1500 animals. Total body irradiation and/or cortisone were used, in the hope of reducing host resistance. Because M. leprae in man grows best where the temperature is lower, the cooler parts of animals were inoculated. In all experiments, heat-treated inoculum was given to control animals. Histopathologic studies of the inoculation sites were made regularly. 2- Thirteen completed experiments on albino hamsters, white mice, white rats, hairless mice, and white guinea pigs have given negative results. 3- The histiocytic granulomatous lesions, in the testes and ears of the golden hamster approximately 18 months post inoculation, resembled human lepromatous leprosy in their histologic pattern, their number of intracellular acid-fast bacilli, and the presence of bacilli within nerves...