318 PHARMACEUTICAL BACTERIOLOGY 



4. Spiroehata vincenti. Pathogenic; causes throat inflammation 

 (Vincent's angina). 



5. Treponema pallidum. The specific cause of syphilis. Often 

 other related organisms are found associated with it. This organism 

 stains with difficulty. 



6. Trypanosoma Gambiense. This is the cause of the dread sleeping 

 sickness of Africa. The transmitter of the infection is the tsetse fly 

 (Glossina palpalis). Investigations have shown that the destruction 

 of the tsetse fly would also eradicate the disease (Koch), which has 

 practically depopulated large districts in Africa. Related organisms 

 cause diseases in horses (surra, dourine and mal de caderas). There 

 are also many trypanosomes of frogs, fish and birds, but these are 

 probably harmless to man. 



PIG. 85. A, Spirocheta refringens; b, Spirocheta pallida. The cause of syphilis. 



III. FLAGELLATA. (Mastigophora). Most of the organisms belonging 

 to this group are ameboid. There may be a fairly distinct cell membrane, 

 and some have a distinct mouth part or end, the so-called cytostome, which 

 leads to a blind oesophagus. They contain flagellae, in addition to pos- 

 sessing an ameboid movement. Some of the representatives of this group 

 appear to have a complex internal structure. The earlier stages may be 

 without flagellae and may be readily confused with amebas. 



Species of Leishmania cause sores and ulcers (in tropical countries). 

 Certain tropical Lamblia and Trichomonas species may cause intestinal and 

 other disturbances. 



IV. INFUSORIA. (Ciliata). These have numerous very fine cilia and 

 contractile vesicles. The bodies are oval and may be free swimming or 

 attached. They have a complex internal structure and are supposed to 

 be the highest of the entire group of protozoa. There is a distinct body 

 covering or membrane and a distinct mouth part. They are essentially 

 saprophytic scavengers being abundant wherever there is an abundance of 

 organic matter in water. They are wholly aquatic in habit. 



