896 THE ANIMAL CARRIERS OF DISEASES 



Nematode Infections. 



{These are on the same lines as trematode and cestode as a rule.) 



Nematode. 



Defini- 

 tive 

 Host. 



Defini- 

 tive 

 Reser- 

 voir. 



Infection. 



Intermediate. 

 Host. 



■ 



Transmission . 



Filaria 

 hancrofti. 



MaE. 



Man. 



Microfilaria 

 in blood. 



Ingestive. 



Culex and 

 Stegomyia. 



Larvofilaria. 

 Penetrative. 



Loa loa. 



Man. 



Goat (?), 

 sheep (?). 



Microfilaria. 

 Ingestive. 



Species of 

 chrysops. 



(?) 



Dracunculus 

 medinensis. 



Man. 



Man. 



Larvae in 

 water. 



Ingestive. 



Species of 

 Cyclops. 



Water. 

 Ingestive. 



A scaris 

 lumbricoides . 



Man. 



Pig. 



Eggs. 

 Ingestive. 



Rats. Larvae on food . 



Ingestive. 



i 



it has deposited its larvae on the skin of sheep and become a pro- 

 ducer of myiasis thereon. 



Myiasis will form the subject-matter of Chapter LXVII. (p. 1619), 

 and here it is only necessary to say that the larvae may be deposited 

 in the natural cavities of the body, placed in neglected wounds, live 

 in the subcutaneous tissue, or pass through the alimentary canal. 



In this chapter we are merely concerned with the method by 

 which the larva reaches man, and it would appear that it is always, 

 or nearly always, due to the direct action of the mother fly; but 

 there is a curious observation, which is that an intermediary animal 

 carrier exists, at all events, in the case of Dermatobia cyaniventris, 

 which has been studied by Blanchard, Surcouf, Rincones, Tovar, 

 Zepeda, and Sambon. 



According to the last-named observer, D. cyaniventris lives in 

 Trinidad and Central and South America, and its young produce 

 cutaneous myiasis in man, monkeys (the brown howler and the 

 capuchin), pumas, agoutis, cattle, goats, pigs, and birds (the toucan 

 and the turkey). 



Man is most liable to be infected while working in the mahogany 

 forests of Honduras and Columbia, as many as a hundred maggots 

 being found in a single patient. These maggots are called by the 

 natives ' mosquito worms,' because they are deposited by a 

 culicine mosquito, Janthinosoma lutzi. 



