“…The course of tuberculosis in vaccinated guinea-pigs in the present investigation was very similar to that observed in previous experiments (Pagel, 1937). I n the vaccinated animals there was an almost immediate response at tho site of infection in the form of a papule which regressed and did not develop into a scab or ulcer ; in the controls the first visible reaction appeared within 8-12 days and progressed to pustule, scab and ulcer formation.…”