Short History of Infectious Anemia. 7 



break of the disesise was in about the year 1895 in the 

 province of Hidaka, Hokkaido and in Yokohama of 

 Aomori Prefecture. However, we have no evidence to 

 decide in which of these two districts the disease first 

 appeared. The reason why the disease occurred in 

 places so far separated from each other is not hard to 

 find, since in former days horses were very often trans- 

 ported by Japanese boats between Hidaka, Yokohama and 

 Noheji. In Hokkaido the disease spread from Hidaka 

 into the plains of Tokachi, Kushiro and Kitami. In 

 Hondo, the main island of Japan, on the other hand, the 

 invansion started in the west from the above centre, 

 Yokohama, proceeded to Akita prefecture (mainly Yuri 

 country), then to the boundary of Tsugaru and stopped 

 in the neighboring county, Akumi of Yamagata Pre- 

 fecture. To the east it entered the adjacent Ichinohe 

 County, Iwate Prefecture, then Sannohe County at the 

 boundary of Aomori Prefecture. Thence it affected 

 horses of the pasturing districts of Iwate Prefecture. 

 Local outbreaks were noticed in the pastures of Fuku- 

 shima and Iba(raki Prefecture ; these undoubtedly were 

 due to the sale of convalescent horses. In the same 

 way the disease came into the prefectures of Tochigi, 

 Gumma, Saitama, Chiba and Yamanashi, and many pati- 

 ents were produced there. Since in these districts horses 

 are not raised in pastures, no fresh cases have been 

 recorded in the neighborhood. 



It may be concluded that the disease is confined to 

 a part of Hokkaido and several district of the north- 

 eastern part of Hondo, and does not invade the southern 

 part of Japan, because the pasturing is restricted in the 

 north, this being one of the necessary conditions for the 

 transmission of the disease. 



The exact number of yearly losses is also unknown 



