GENUS: OIKOMONAS 291 



Under the name of Oikomonas granulata YakimofE, Solowzoff, and 

 Wassilewsky (1921) describe a small flagellate isolated by them by inocu- 

 lating agar plates with the stools of two cases of diarrhoea in Petrograd. 

 They distinguish the organism from the free-living form 0. termo on 

 account of the presence of certain granules in the cytoplasm. Yakimoff, 

 Wassilewsky, KornilofT, and Zwietkof? (1921) state that they have isolated 

 0. termo from the fa?ces of guinea-pigs and mice by employing the same 

 technique. Another form isolated from guinea-pig faeces is described 

 as Sphceromonas rossica, and one from rabbit faeces as Piromonas rossica. 

 The description of these forms is most unsatisfactory, and there are no 

 grounds whatever for the assumption made that the flagellates were 

 actual parasites of man or animals. They were undoubtedly dealing 

 with free-living forms which had passed through the intestine in the 

 encysted state, or, what is more probable, with flagellates in water con- 

 taminating the vessels in which the samples of faeces were collected. 



The writer has seen an organism of the Oikomonas type in the tortoise 

 Testudo calcarata. The body is spherical or ovoid, and possesses a single 

 long flagellum. When spherical, the body varies in diameter from 5 to 16 

 microns. There is a nucleus with large central karyosome, while the 

 axoneme of the flagellum arises from a blejjharoplast near the surface of 

 the body. 



The organisms discovered in human faeces by Kofoid and Swezy 

 (19216), which they regard as representing two species of Craigia (see 

 p. 29-1), not improbably belong to the genus Oikomonas. 



Blackhead of Turkeys. 



This disease, which takes the form of an entero-hepatitis associated 

 with black discoloration of the head, especially in young turkeys, may 

 be considered here on account of its association with a flagellate infection. 

 Theobald Smith (1895) described as Amoeba meleagris certain structures 

 which he found in the intestinal and liver lesions. Cole and Hadley (1910) 

 believed that the amoebae were really the schizogony stages of a coccidium 

 which it was supposed had been acquired from sparrows. Theobald 

 Smith and Smillie (1917), however, showed that the coccidium of the 

 sparrow was an Isospora, while that of the turkey was an Eimeria. 

 Hadley and Amison (1911) came to the conclusion that the lesions were 

 not due to a coccidium, but to TricJiomonas which had invaded the tissues 

 and become mostly aflagellate amoeboid bodies. Jowett (1911a), working 

 in South Africa, came to the same conclusion. Hadley (1916, 1917), 

 after further investigations, stated that he had actually seen flagella 

 on some of the tissue forms, and was still further convinced of their 



