104 MORE MINOR HORRORS 



ture. It can be introduced into a new locality 

 by the arrival of an infected mosquito, or by 

 the arrival of an infected human being. In 

 the former case the disease breaks out within 

 a few days ; in the latter at least ten or twelve 

 days elapse before new cases arise, for, as we 



Fig. 26. — Stegomyia fasciata. Female, lateral view 

 (magnified.) Note hump-backed outline, and also the 

 position of the posterior pair of legs. 



shall see later, the organism, whatever it is, 

 that causes the fever is not capable of passing 

 from the mosquito until it has been in its body 

 for ten or twelve days. 



Thirty-six years ago Finlay of Havana 

 suggested that the virus of yellow fever was 

 inoculated by mosquitos ; but it was not until 

 the publication of the discoveries by Sir 

 Ronald Ross and others, that malaria is trans- 

 ferred by Anopheles, that a thorough investi- 

 gation of yellow fever was made. In the last 



