264 PUBLIC HEALTH BACTERIOLOGY 



invaded widely separated districts, was notable in several 

 important particulars. The epidemic was almost without 

 exception one of primary pneumonic plague. The fatality 

 was extremely high, few cases of recovery having been 

 reported. The infectious nature of the malady was very 

 great, and the virus was apparently carried by the sputum. 

 The origin of the plague was not ascribed to rats, but to 

 marmots, a species of squirrel living in burrows. The 

 question of infection by fleas is here of minor 'importance, 

 once the epidemic is started. Its relation to the origin of 

 the epidemic has not been worked out. Once begun, the 

 propagation was apparently by direct inhalation of the 

 virus. 



The Chinese Government invited the other Governments 

 to send representatives to an International Plague 

 Conference, which began its sittings at Mukden on April 

 3rd, 1911. The following statements are taken from the 

 reports of the proceedings published in the Lancet from 

 April 29th, 1911, onwards, which include an exhaustive 

 report by Dr. G. Douglas Gray, physician to H.B.M. 

 Legation, Peking, the questions for discussion, and the 

 Chairman's inaugural address. 



Origin. It had been known for many years that in 

 Eastern Siberia and Mongolia the marmot, or tarabagan 

 (Russian), or han ta (Chinese), a variety of the squirrel 

 tribe, of the rodent genus, frequently suffers from a fatal 

 disease which may be transmitted to man and produce 

 symptoms indistinguishable from bubonic and pneumonic 

 plague. This animal is hunted for its fur, which is used 

 to imitate sable and other furs. One of its favourite 

 haunts is a mountain range in the north-west of Man- 

 churia, and here large numbers of Chinese are employed 

 trapping it during the summer months. It was among 

 these trappers that the present outbreak is held to have 

 originated. The proof that the " tarabagan disease " in 

 man, and plague, were one and the same disease, has 

 not been given bacteriologically, and in 1905, 1906, and 

 1907, Russian scientific expeditions were sent to investi- 

 gate and report. Dr. M. T. Schreiber concluded that : 

 (i) Epizootics (a term applied to those animal diseases 

 which behave as epidemics do in the human species) 



