Mosquitoes and Yellow Fever 



199 



with a crape, or any appearance of mourning was shunned 1 ke a 

 viper. And many valued themselves highly on the skill and address 

 with which they got to the windward of every person they met. 

 Indeed, it is not probable that London, at the last stage of the plague, 

 exhibited stronger marks of terror than were to be seen in Phila- 



132. Anopheles crucians. Female (x4). After Howard. 



delphia from the 24th or 2Sth of August imtil pretty late in Septem- 

 ber." 



Such was the condition in Philadelphia in 1793 and, as far as 

 methods of control of the disease were concerned, there was practi- 

 cally no advance during the last century. The dominant theory 

 was that yellow fever was spread hy fomites, that is, exposed bedding, 

 clothing, baggage, and the like. As late as 1898 a bulletin of the 

 United States Marine Hospital Service stated : 



