1 62 SOME MINUTE ANIMAL PARASITES 



carries the virus of the disease. When the decay of 

 the trading powers of the southern European nations 

 set in, the trade routes gradually crept northwards, 

 and the west coast of France, Belgium, and Holland, 

 and the German and English ports, particularly of 

 the south and west, took over the commerce formerly 

 restricted to the Mediterranean. It was then that 

 the cases of yellow fever that have visited England 

 were chiefly notified. 



The original home of yellow fever seems to have 

 been the islands of the West Indies, as many of the 

 early explorers found to their cost. Even as early 

 as 1495 the malady is supposed to have attacked the 

 men under Christopher Columbus, and was carried 

 by the Spaniards to the mainland. To-day the 

 Eastern Atlantic coast in the tropical zonesls the 

 chief home of yellow fever. The mouths of the 

 Amazon and Orinoco, the coast of Central America, 

 Mexico, and parts of the United States bordering on 

 the Gulf of Mexico, together with the West Indies, 

 seem to form the principal centre of the disease. 

 West Africa has a bad reputation, but there is some 

 evidence that yellow fever was carried by ships to 

 the Cape Verde Islands in the early years of the 

 sixteenth century, and was spread to the Gulf of 

 Benin from there about 1520. Now it is perhaps to 

 be considered as a second centre, in which serious 

 outbreaks have occurred in the past and where it is 

 likely that some cases are always present. 



Many British interests are bound up in West 

 Africa, and British trade is constantly increasing 

 there. Its great natural resources provide not only 



