MASTIGOPHOEA. 



23 



harmful to their hosts. Some, however, are markedly patho- 

 genetic, including the following : — 



Trypanosoma hrucei (Plimmer and Bradford), producing 

 JSTagana in horses and cattle in Africa ; 



T. equiperdum (Doplein), the cause of "Dourine" in horses; 



T. evami (Steel), the " Surra " of horses and cattle ; 



T. equinum (Voges), the agents of " Mai de caderas " in horses 

 in S. America ; 



T. (jamhieme (Button), the parasite of Sleeping Sickness and 

 Gambia Fever in man in Africa ; and 



T. cruzi (Cruz), which produces "Basilero" in man in S. 

 America. 



T. h-ucei occurs as a natural parasite in wild game, such as 



Fig. 4. — a, A Trypanosomc. li, A Sjnrocliwtet (Greatly enlarged.) 



buffaloes, antelope, &c., in Africa, and does no harm to them ; 

 in S. America T. equinum is a natural parasite of the Capybara, 

 but directly they get to horses and cattle their evil effects are 

 felt. Trypanosomes have a secondary host, which is an inverte- 

 brate, which acts as an intermediary between the vertebrate 

 hosts, with one exception — namely, T. equiperdum — which is 

 said to be transmitted by means of coitus. 



The intermediate host, of these parasites of terrestrial verte- 

 brates are blood-sucking insects. Tsetse-flies (Glossina), in Africa, 

 and a Bug (Conm'hinus megistus) is known to be the secondary 

 host of Basilero. The secondary hosts of the parasites of aquatic 

 vertebrates are leeches. 



Reproduction is sexual and asexual, tlie sexually differentiated 



