A NATURALIST IN BRAZIL 



in the Oswaldo Cruz Institute, which looks over the bay from one 

 of the suburbs of Rio : a fine building in the Moorish style. Through- 

 out Brazil, moreover, an Assistencia publica has been organized, and 

 in each State there is a Department of Hygiene. I saw in OUnda 

 how carefully and thoroughly the foci of infection were attacked. 

 The infected house is at once marked by a yellow flag, which 

 means that no one may enter it. It is then, with the neighbouring 

 houses, completely covered with great linen cloths — in the case of 

 one-storied houses this is possible — and is then "gassed" with 

 poisonous vapours, so that all the mosquitoes are killed. Every day, 

 moreover, officials visit all the houses in that quarter of the city, 

 in order to drain any accumulations of water, or to disinfect them, 

 or place small fish in them ; these are a species of carp, which will 

 live even in the smallest puddles, and devour the mosquito larvae. 

 In the monastery these fish were placed in the cistern on the roof 

 which supplied the house with water. And it is the law in Rio that 

 every garden pond or stream must contain fish. 



When I travelled by the electric tramway from Recife to Olinda, 

 through the mangrove swamps, the hands and faces of the passengers 

 wer sometimes covered with tiny black flies, which sucked their 

 blood and gave rise to an unpleasant irritation. The Brazilians call 

 these flies, which are no bigger than a pin's head, "Maruim" or 

 "dust." We have just such midges in Germany. Their larval state, 

 like that of the mosquito, is passed in the water. 



I never suffered while in Brazil from the gadflies or Motucas. In 

 some parts these buzzing flies are said to make themselves unpleasant. 

 One species of gadfly, the "Bicho berne," is greatly dreaded. Its 

 eggs are deposited not only on the hides of cattle, but also on the 

 skin of human beings. From these eggs maggots emerge, which grow 

 and feed under the skin, while a large boil forms over them. When 

 the maggots turn in the wound which they have made they are 

 said to cause acute pain. Dr. Bethke, a physician of Espirito Santo, 

 assured me that the people extract the maggot by laying a piece of 

 bacon on the place ; it eats its way through this, as it can no longer 

 obtain any air. At a later stage the maggot bites its way out in any 

 case, falls to the ground, and pupates. It is a remarkable fact that 

 these flies do not lay their eggs directly on their victims, but on the 

 necks of other flies or mosquitoes. These rub them off* on men and 

 animals, who receive the parasites without knowing how they arrived. 

 Many gadflies convey disease. In the interior of Brazil donkeys and 

 other draught animals suffer from a lameness of the hip-joint, known 



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