LATER WORK 7 



worms, parasitic in certain animals, passed portions 

 of their life-cycles within the bodies of certain other 

 animals or insects, now called intermediate hosts. At 

 the same time Manson came to the same conclu- 



Anopheles 



sion when in China, and he made his now famous dis- 

 covery that the embryos of Filaria bancrofti de- 

 velop in the tissues of mosquitos which had fed on 

 infected Chinamen, and which had been caught in 

 their houses. However, the final transfer of the 

 nearly developed embryo worm from the mosquito to 



