TRYPANOSOMES OF ANTELOPES 507 



of the leishmania type. Galli-Valerio (1923) claims to have produced a 

 similar infection in a rat. If these results are accurate, this is the only 

 known instance of a trypanosome producing a leishmania infection without 

 the occurrence of trypanosomes at the same time. Hoare (1921cr) in the 

 case of rats, mice, and guinea-pigs, and Buchner (1922) with mice, failed 

 entirely to produce any infection with these flagellates. 



Examining ticks {Ixodes ricinus) from sheep. Bishop (1911) claims to 

 have seen a single crithidia form in the tick. It is possible this was a 

 cultural form of the sheep trypanosome. 



Trypanosomes of Antelope. 



Button, Todd, and Tobey (1906) described as T. tragelajjhi a large 

 trypanosome from the blood of a West African bush buck, Trogelaphus 

 sylvaticus (Fig. 210, 2). Kleine and Fischer (1911) found a similar form 

 in the reed buck, Cervicapra arundinum, near Tanganyika, and Rodhain, 

 Pons, Vandenbranden, and Bequsert (1913a) one in Cephalopus grimmi 

 and Cohus vardoni in the Congo. It does not seem improbable that 

 these forms are actually Trypanoso7na theileri. Bruce, Hamerton, Bate- 

 man, and Mackie (1909a) discovered a much larger form in the reed buck 

 {Cervicapra arundinum), in the bush buck {Tragelaphus sylvaticus), and 

 in an ox in Uganda. On account of its large size it was named Trypano- 

 soma ingens (Fig. 210, 5). It measures from 72 to 122 microns in length 

 and 7 to 10 microns in breadth. The trypanosome was also seen by 

 Eraser and Duke (1912a) in the blood of a bush buck in Uganda. From 

 the dimensions given, it will be seen that it is distinctly larger than any 

 known form of T. theileri, and on this account is possibly a distinct species. 

 Nothing is known of its life-cycle. A trypanosome of the same type was 

 seen by Dodd (1912) in the blood of two mouse deer {Tragulus javanicus) 

 which had died in the Zoological Gardens of Sydney. Bruce et al. (1913c) 

 gave the name Trypanosoma cephalophi to a large form seen by them in 

 the blood of the duiker, Cephalophus grimmi (Fig. 210, i). 



Group B. Trypanosomes which Develop in the Anterior Station in the 

 Invertebrate or have become Secondarily Adapted to Direct Passage 

 from Vertebrate to Vertebrate. 



1. PATHOGENIC TRYPANOSOMES TRANSMITTED BY BLOOD-SUCKING 



ARTHROPODA. 

 General Remarks on the Pathogenic Trypanosomes. 



Under this heading are included certain trypanosomes which produce 

 disease in man and domestic animals. As stated above, the true verte- 

 brate hosts of these trypanosomes, in tsetse fly areas of Africa at least, 



