534 Animal Biology 



Certain diseases of animals other than man are produced by Protozoa. 

 The following are typical and representative: Opalina (class Infusoria) 

 is responsible for a parasitic condition in the intestine of frogs (Fig. 265) . 

 In the class Mastigophora, Histomonas meleagidis produces ''black-head" 

 of turkeys; Trypanosoma hrucei (Fig. 266) is carried by the tsetse fly 



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Fig. 265. 



Fig. 266. 



Fig. 265. — Opalina ranarum, a protozoan of the class Infusoria, is parasitic in 

 frogs, worms, and mollusks. 



Fig. 266. — Trypanosoma hrucei of the class Mastigophora causes the deadly 

 Nagana disease of various animals in Africa. This parasite is transmitted by the 

 tsetse fly {Glossina sp.) (Copyright by General Biological Supply House, Inc., 

 Chicago.) 



Fig. 267. — Babesia bigemina, a protozoan of the class Sporozoa, causes Texas fever 

 in cattle. Four stages in red blood corpuscles are shown. 



(Glossina morsitans) and causes the tsetse fly disease of cattle; Trypano- 

 soma evansi produces a disease known as surra in cattle and horses; 

 Trypaiiosoma equiperdum is responsible for the disease called dourine in 

 horses. In the class Sporozoa, Monocystis parasitizes the seminal vesicles 

 of the earthworm (Fig. 77) ; Coccidia produces red dysentery in calves; 

 Babesia bigemina (Fig. 267) causes Texas cattle fever; Nosema bombycis 



