XIl] HISTORY 203 



Manson, 1891. Microfilaria nocturna Manson, 1891. F. phi- 

 lippinensis Ashburn and Craig, 1906. 



History. The embryo of this species was discovered by 

 Demarquay in 1863, in the chylous fluid from a case of dropsy 

 of the tunica vaginahs, occurring in the West Indies. Wiicherer 

 in 1866 noticed the parasites in the urine of several cases of 

 tropical chyluria, and in the next few years these embryos 

 were found in similar cases from various parts of the world. 

 In 1872 Lewis found that the parasites occurred in the blood 

 of man, and Manson, da Silva Lima and Crevaux established 

 the identity of these blood filarise with those occurring in cases 

 of chyluria and tymph scrotum. In 1876 the adult filaria 

 was discovered by Bancroft in an abscess of a lymphatic gland 

 of the arm and also in a hydrocele of the spermatic cord. 

 Manson studied the disease in China, and was the first to notice 

 the periodic increase and decrease in the number of parasites 

 in the peripheral circulation. From these observations he 

 deduced that some blood-sucking insect was responsible for 

 the spread of the infection, and his discovery in 1878 that 

 mosquitoes were the agents in the transmission of the disease 

 constitutes one of the landmarks in the history of tropical 

 medicine. In 1879 he described the changes undergone by 

 the filaria in the body of the mosquito, Culex pipiens, but the 

 method in which the parasite again reached man remained 

 undiscovered till 1900, when Low observed the worms in the 

 proboscides of mosquitoes infected with Filaria bancroffi. 



Distribution. This species has been recorded from tropical 

 and subtropical countries in most parts of the world. In 

 Europe one case has been observed in Spain and another in 

 Italy ; it is also probable that it occasionally occurs in Greece 

 and Turkey. In Asia this filaria is widely spread throughout 

 China, Japan, the Philippines, and India. It is rare in Indo- 

 China. In Oceania it is extremely common in the majority 

 of the islands, and in Samoa at least one half the inhabitants 

 are said to be infected. In Australia it occurs as far south as 

 Brisbane. In Africa it has been recorded from many locahties 

 in the north, east and west, and probably occurs throughout the 

 whole continent north of latitude 20° S. It is also common 



