CHAPTER LV. 

 THE AMOEBA. 



Introduction. 



Section I. Amoeba princeps, p. 745. 



Section II. The intestinal amoebae, p. 746. 



Introduction, p. 746. 



Microscopical appearance, p. 747. 



I. Amoeba coli, p. 747. II. Amoeba histolytica, p. 748. 



Methods of detection. Staining methods, p. 748. 



Cultivation, p. 750. 



Experimental infection, p. 751. 



FOB some years past the Protozoa have assumed a position of considerable 

 importance in human and veterinary pathology. In this and the following 

 chapters the various pathogenic species will be briefly described and the 

 methods suitable for their detection and study indicated, but all reference 

 to the classification and biology of the Protozoa will be omitted. For these 

 the reader is referred to treatises devoted to the study of Protozoology. 



Among the Rhizopoda, the Amoeba) alone are of interest from the point of 

 view of pathology. Amoebae are frequently found in the human intestine, 

 and one species is the cause of the endemic dysentery of warm climates ; 

 other species have been found in ulcerations of the mouth, in dental tartar 

 (Amoeba buccalis ; Gross, Sternberg, Kartulis), in haematuria, cystitis and 

 metritis (Amoeba urogenitalis vel vaginalis ; Boeltz, Rossi Doria and others) 

 and in the fluid of some malignant abdominal tumours (Miura, Lieberkiihn, 

 Leyden). 



Before embarking upon a study of the pathogenic amoebae it will be as 

 well to acquire a certain amount of practice in observing these protozoa, and 

 for this purpose the Amoeba princeps, a very widely distributed saprophytic 

 species, may be used. 



SECTION L AMCEBA PRINCEPS. 



The Amoeba princeps is not only a very suitable species for purposes of 

 observation, but specimens can be readily obtained by macerating a little 

 straw in a vessel of water. In such an infusion numerous bacteria will be 

 found, and in addition to other Protozoa, amoebae appearing as large masses 

 (100/x in diameter) of granular protoplasm can be seen after a few days. 



The amoeba consists of an hyaline ectosarc surrounding a granular endosarc which 

 contains several contractile vacuoles, and a rounded refractile nucleus which can be 



