502 FAMILY: TRYPANOSOMID^E 



Trypanosomes of Sheep. 



Trypanosoma melophagium (Flu, 1908). — Synonyms: CritMdia melophagia 

 Flu, 1908; Leptomonas Roubaud, 1909; L. melophagi Mesnil, 1909; C. melophagi 

 Swingle, 1909; Sheep-trypanosome Woodcock, 1910; CritMdia Wenyon, 1913; 

 L. melophagia Brumpt, 1913; T. woodcoclci Brumpt, 1913; Herpetomonas melopliagia 

 Doflein, 1916; Trypanosoma {Cystotrypianosoma) melophagia Bnimpt, 1922. 



This trypanosome, the developmental stages of which in the sheep ked 

 {Melo])hagus ovinus) were the first forms to be discovered, was seen by 

 PfeifEer (1905), w^ho referred to it as a " trypanosome-like flagellate." Flu 

 (1908) described the ked flagellate as Critliidia tnelophagia, and, like its 

 original discoverer and many subsequent observers, including Roubaud 

 (1909), Porter (1910), Swingle (1911a), Dunkerley (1913), regarded it as an 



Fig. 212. — The Sheep Ked, Melophagus ovinus (9), and its Pupa, the Trans- 

 mitter OF Tryjmnosoma melophagium ( x 8). (After Hoare, 1923.) 

 The scale shows the natural size of the fly. 



organism peculiar to the ked. Woodcock (1910), however, observed a 

 trypanosome in the blood of an English sheep, and suggested the possibility 

 of the ked flagellate being merely the invertebrate phase of this parasite. 

 The trypanosome of sheep was again seen by Behn (191 1, 1912) in Germany, 

 and its relation to the ked flagellate was investigated by Noller (1917) 

 and Kleine (1919a). Noller obtained cultures of both the sheep trypano- 

 some and the ked flagellate, and showed that the cultural forms were 

 identical. He noted that flocks of sheep which were most heavily infested 

 with keds were likewise most heavily infected with trypanosomes, and he 

 concluded that the ked flagellate was actually the developmental form of 



