THE LIFE HISTORY OF CESOPHAGOSTOMUM APIOSTOMUM: 

 I. DEVELOPMENT OUTSIDE OF THE HOST 



By Ernest Linwood Walker 

 {From the Biological Laboratory, Bureau of Science, Manila, P. I.) 



Four plates 



In 1905 Brumpt reported a case of oesophagostomiasis in a 

 Negro from the Omo River near Lake Randolph in East Africa. 

 The worm in this case was described by Railliet and Henry 

 (1905) under the name (Esophagostomum brumpti. 



Thomas, in 1910, found a fatal case in a native of Manaos, 

 Brazil, and described the pathological anatomy and histology 

 of the case very completely. The worm in this case was like- 

 wise referred to Railliet and Henry for identification. These 

 authors described the parasite under the name CEsophagostomum 

 stephanostomum var. thomasi Railliet and Henry, 1910. 



Leiper, of the London School of Tropical Medicine, in 1911, 

 found among the hookworms collected by Doctor Foy, of the 

 West African Medical Staff, 6 oesophagostoma, which had been 

 passed in the stools of a native at Ibi, North Nigeria. Leiper 

 identified the worms in this case as (Esophagostomum apiosto- 

 mum Willach, 1891, a species common in the intestine of apes. 

 Furthermore, this author is of the opinion that O. brumpti 

 Railliet and Henry, 1905, is identical with 0. apiostomum 

 Willach. 



These are the only cases of the infection of man with this worm 

 that have so far been reported, but Weinberg (1908) believes 

 that the few cases in man so far reported in Africa are due to 

 the fact that necropsies on Negroes are rare in the African 

 colonies and that attention has been directed especially to para- 

 sites of the blood. 



Beside man and apes, cattle, sheep, goats, pig, and Dasypus 

 are subject to oesophagostomiasis, but in these latter animals 

 the infection is due to other species of (Esophagostomum. 



CEsophagostomiasis is characterized by hsemorrhagic cysts or 

 tumors in the submucosa or muscularis of the large intestine — 

 rarely of the small intestine — which project usually both inside 

 and outside of the gut, and which contain the immature adult 

 cesophagostomum. At maturity the cyst ruptures and the adult 



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