THE HEMOFLACELLATES 43 



The following outline classification of trypanosomes of veterinary and medical im- 

 portance is based on Hoare (1957, 1959). Sections on metabolism based on von Brand 

 (1956), Ryley (1956) and von Brand and Tobie (1959), and a section on avian trypanosomes 

 have been added. 



I. PARASITES OF MAMMALS 



A. Morphology in Mammal 



Kinetoplast not terminal, large. Free flagellum always present. Posterior 

 end of body pointed. Division in crithidial, leishmanial or trypanosome stages. 



Biology 



Multiplication in mammal typically discontinuous. Development of metacyclic 

 trypanosomes in hind gut (posterior station) of vector (in T. raiigeli also in 

 salivary glands: anterior station). Transmission contaminative thru feces (in 

 T. rangeli also inoculative). Except for T. cruzi. trypanosomes slightly or not 

 pathogenic. 



Metabolism 



Blood forms have high respiratory quotient and low sugar consumption, produc- 

 ing acetic, succinic and lactic acids aerobically and succinic, lactic, acetic and 

 pyruvic acids anaerobically. Cyanide markedly inhibits oxygen consumption. 

 Sulfhydryl antagonists moderately inhibit oxygen consumption. Culture forms 

 have high respiratory quotient and moderately high sugar consumption, produc- 

 ing acetic and succinic acids aerobically and succinic and acetic acids anaero- 

 bically; cyanide markedly inhibits oxygen consumption; sulfhydryl antagonists 

 moderately to markedly inhibit oxygen consumption. Cytochrome pigments, 

 cytochrome and succinic oxidase activity are present in T. cruzi and T. lewisi. 



1. LEWISI GROUP 



a. Mode of reproduction unknown. 

 T. nielophagium of sheep. 



b. Reproduction by binary fission in crithidial stage. 

 T. theileri of cattle. 



c. Reproduction by multiple fission in crithidial stage. 

 T. lewisi of rats. 



T. duttoni of mice. 



d. Reproduction by binary fission in leishmanial stage. 

 T. cruzi of man, dog, opossum, monkeys. 



e. Reproduction by multiple fission in leishmanial stage. 

 T. nabiasi of rabbits. 



f. Reproduction by binary fission in trypanosome stage. 

 T. rangeli of man, dog, opossum, monkeys. 



