SNAKES AND BLOODSUCKERS 



person, and make their way into the red corpuscles, and he too 

 falls ill of malarial fever. 



In order to be inoculated with malaria the mosquito must first 

 bite a malarial patient, that is, malaria must exist in the neighbour- 

 hood. But this is by no means the case all over Brazil, so that 

 thousands and thousands of Brazilians are bitten by mosquitoes 

 without falling ill. And it must not be supposed that mosquitoes 

 are a pest only in the tropics! Neither in Ceylon nor in Brazil 

 have I suffered from mosquito-bites as I have done at Karlsruhe 

 or in Alt-Breisach. In Brazil I encountered whole swarms of mos- 

 quitoes only in Ribeirao; at night they hummed round my bed, 

 but I spread the mosquito-net which I always carry with me over 

 my bed, and I was not bitten. One should always have a mosquito- 

 net at hand in Brazil, except perhaps in the large towns and the 

 mountains, for one is in greater danger of mosquito-bites at night, 

 since the malarial mosquitoes do not begin to bite until it is dark. 

 My good mosquito-net served me well when I was in southern 

 Pernambuco, in a bad malarial district, for quinine prophylaxis 

 (fifteen grains every Friday, and half as much on Sunday) is not 

 certainly effective unless one continues it for six months after leaving 

 the malarial region. 



Worse than malaria is yellow fever. This is conveyed by a mos- 

 quito speckled with black and white, which has a dark triangle on 

 its back. This insect is given to biting as twilight falls, and, as Dr. 

 Lutz observes, is both shy and importunate. Yellow fever, which 

 is generally fatal to Europeans — two German ladies died of it 

 while I was in Pernambuco — was formerly the scourge of Brazil, 

 especially in the seaports, and at one time in Santos the sailors 

 could escape death only by taking the train directly they landed, 

 and going to a sanatorium in the mountains, returning only after 

 their vessels had been laden by natives, whereupon they went 

 aboard and weighed anchor. New-comers were particularly liable 

 to the worst form of the disease. The business men of Rio had 

 discovered that they remained in health if they only worked in 

 Rio, and went to Petropolis to pass the night. The embassies too 

 established themselves in Petropolis. 



It is owing to Dr. Oswaldo Cruz that Rio and Santos are to-day 

 free from yellow fever, and that only isolated cases occur from time 

 to time in the northern ports. Actual epidemics are things of the 

 past. Dr. Cruz accompanied the campaign against the fever by a 

 campaign against the mosquitoes. To-day his work is still carried on 



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