XX] POLIOMYELITIS 365 



labium of their intermediate host. When an infected Stomoxys 

 bites another animal the filariae escape from the labium and 

 probably bore through the skin of the host in the same way as 

 F. bancrofti, but this part of the life-cycle has not yet been 

 observed. Noe found that in Italy, where his experiments 

 were performed, only three to four per cent, of the Stomoxys 

 became infected, the remaining 96 to 97 per cent, being appar- 

 ently immune to infection. 



Although there is little doubt that S. calcitrans is capable 

 of transmitting this filaria, it is important to add that up to 

 the present no one has been successful in actually infecting 

 cattle by the bites of infected flies. 



REFERENCES. 

 Alessandrini. Rendiconti Accad. d. Lined, vol. xii. pp. 387-393. 

 Neumann-Macqueen (1905). Parasites and Parasitic Diseases of 



Domesticated Animals. London : Bailliere, Tindall & Cox. 

 Nod, G. (1903). Studi sul ciclo evolutivo della Filaria labiato-papillosa. 



Rend. Accad. d. Lincei, vol. xii. pp. 387-393. 



Poliomyelitis. 



Synonyms. Epidemic Poliomyelitis ; Infantile Paralysis ; 

 Epidemische Kinderlehrnung. 



History. Poliomyelitis has been endemic in Northern 

 Europe for many years, especially in Scandinavia, but it was 

 only in 1907 that the disease suddenly began to extend its 

 range of distribution. During the past two or three years 

 many countries in different parts of the world have been 

 visited by epidemics, the origin of which has remained quite 

 unexplained. In America there is no previous history of a 

 general epidemic until 1907, although local outbreaks had 

 occasionally been noticed. Since this date, however, the dis- 

 ease has been prevalent during the summer and autumn in many 

 parts of the United States and Canada. It is possible that the 

 infection may have been introduced from Scandinavia, for the 

 two great centres of the recent epidemic were the Atlantic 

 coast towns and the state of Minnesota, both of which received 

 large numbers of Scandinavian emigrants. But there is no 

 apparent reason why the disease should not have broken out 



