(1) The existence of sporadic cases of natural plague among tarabagans has again been established.
(2) The tarabagan is easily susceptible to pneumonic plague produced by the inhalation of B. pestis in spray form, and may contract, besides the acute infection, chronic type of the lung affection.
(3) Our inhalation experiments have proved contacts to be liable to pulmonary plague infection in both acute and chronic forms. The existence of carriers among tarabagans seems also probable.
(4) Tarabagans can be infected with plague by feeding upon artificially infected food, contracting an alimentary type of the disease. The B. pestis is easily cultivated from the intestinal tract of animals suffering from plague.
(5) Our evidence shows that subacute or chronic plague may exist among tarabagans in Mongolia and Siberia, and thus form a connecting link in the epidemiology of plague in those regions.