556 FAMILY: TRYPANOSOMID^ 



A series of measurements of the infective forms from the hypopharynx 

 of three species of tsetse fiy gave the following average dimensions: 



Glossina tachinoides . . 

 Glossina palpalis 

 Glossina morsitans 



By attention to the features detailed above, Lloyd and Johnson claim 

 that a T. congolense infection can be recognized in tsetse flies (see p. 514). 



It is possible that T. 7nontgo7neryi Laveran, 1909, seen once by Mont- 

 gomery and Kinghorn (1909) in Ehodesian cows, and T. somaliense and 

 T. cellii, described by Martoglio (1911) as the cause of disease in cattle, 

 horses, sheep, and camels in Somaliland, belong to the T. congolense group. 

 The same remark applies to T. frobeniiisi, discovered by Weissenborn 

 (1911) in Hamburg in the blood of a horse which had been brought there 

 from Togoland. T. montgoyneryi or a very similar form was again seen 



/•\' 



O 



Fig. 229. — Tryimnosoma montgomeryi from Blood of Ntasaland Dog (x 2,000). 

 (After Kinghorn and Yorke, 1913.) 



by Kinghorn and Yorke (1912a) in a dog in Ehodesia, and, as it is distinctly 

 broader than T. congolense (1*25 to 6-5 microns), it may be a separate 

 species (Fig. 229). Lloyd has, however, shown the writer a slide of 

 undoubted T. congolense from a sheep in which numerous forms apparently 

 identical with T. montgomeryi occur. The trypanosome found by Eding- 

 ton (1908) in a horse in Zanzibar is probably T. congolense. Writing of 

 this trypanosome, Aders (1923) notes that with the importation of cattle 

 from Africa there are introduced, not only T. congolense, but also T. hrucei, 

 T. vivax, and a trypanosome resembling T. evansi. Of these, only T. con- 

 golense has established itself in the island, and this has taken place in the 

 absence of tsetse flies. Tabanids and possibly other biting flies appear 

 to be the vectors. 



With reference to T. somaliense and T. cellii, Donizio (1921) has reinves- 

 tigated the trypanosomes of Italian Somaliland, and has found that two 

 forms exist^one, of the T. hrucei type, affecting chiefly equidae, and the 

 other, of the T. congolense type, producing disease in cattle. He concludes 



