PROTOZOA IN DISEASE 



317 



I .The amebas are also classed with the Sporozoa, but it has npt been 

 proven that all of the organisms which are classed as ametiaiS fprni> swarm 

 spores; The primary cause of malaria certainly belongs to the sporozoa. 

 Cytologists are gradually recognizing the fact, that. many of the so-called 

 single-celled organisms, such as ameba, Paramecium, etc.,, are not as 

 simple in structure and in physiological activity as was'generally supposed. 

 Many of these organisms contain highly complex cell*constituents which 

 enable them to compete quite successfully in the struggle for existence, 

 with the highly complex multicellular organisms. 



1. Entamoeba co/i.— rlnhabits the large intestine. , Probably harmless. 

 , Amoeba belong here and not in the sporozpa. Mjay be confused with 



phagocytes., 



2. Entammba histolytica. — Causes entero-colitis and dysenteric ulcera- 

 tions. It is also found in abscesses of the liver. Occurs in tropical 

 countries, less common in temperate zones. 



3. Entamoeba buccalis. — Found in dental caries. Probably not patho- 

 genic. , > 



4. Entamoeba undtdans. — Occurs in the intestinal tract. 



5. Leydenia gemmipara. — Identity doubtful. ^Supposed to have a 

 causal relationship to carcinomatosis (cancer). 



II. Flagellata. — Motion due to flagellse. Some possess an undulatory 

 motion. Have been classed as bacteria (Spirillae). 



1 . Spirochata recurrentis {Spirillum obermeieri) . ' — This is the organism 

 which causes relapsing fever. The disease is so designated because 

 after apparent complete recovery, one or more relapses invariably 

 follow. It is not a very fatal disease (4 per cent, of deaths) and is, so far, 

 rare in the United States. It, is and has been very prevalent in parts 



, of Europe. Xhe disease can be transmitted, by inoculation, to man, 

 monkeys, niice and rats. An immunity treatm,ent has been attemp- , 

 ted, with some success. Most authorities class ihe organism as a 

 , fungus (Spirillum). \ , , , 



2. Spirociiatd Duttoni. — ^This organism is , the primary cause of the' 

 South African tick fever (Tete fever), so-called liecause the carrier is a 

 ?,^&ci&s 6i caX^etic^ {Ornithodor as vioubata). 



'3. Spirochoeta Novyi. — Said to be the cause of American relapsing fever.' 



^iThe isystfematic fibsition of the spirociiastes is still in dispute. They probably 

 belong;to the a;ni:nial kingdom. Note the tentative position given them by thecom-i 

 mittee on the; classification of bacteria appointed by the Society of American Bac.teri-. 

 ologists. The fully life history of these orgaisms has not yet been worked out.. What has 

 been described uiid'er, the name r;;'e/'o»eOTa {Spirpchceta) pallidum \s m\]l. -piahabViity' 

 the male genetWtion of this organism, the female cells being irregular in outline ari^' 

 found in the lyrnphoCytes and in other body cells. ' v 



