ILLUSTRATIONS 



(From water-color drawings by Teodosio S. Espinosa) 



Plate I 



The figures in Plate I are all drawn from fixed and stained preparations 

 at the magnification of Zeiss ^o oil-immersion objective, ocular 3, and 

 tube length of 160 millimeters, and with the aid of a camera lucida. 



Fig. 1. Motile form of a typical Amoeba, cultivated from the Manila water 

 supply. Note the small size, central arrangement of the chro- 

 matin in the nucleus, and the contractile vacuole. 



2. Encysted form of the same species of Amozha. Note the small size 



and single nucleus with central arrangement of the chromatin. 



3. Motile form of Entamceba coli from the stool of a healthy person. 



Note the dense, granular structure of the cytoplasm, the rela- 

 tively large amount of chromatin and its peripheral arrangement 

 in the nucleus. 



4. Encysted form of Entamoeba coli, from the stool of a healthy person. 



Note the large size, the relatively thick cyst wall, the 8 ring-form 

 nuclei, and the absence of "chromidial bodies." 



5. Motile form of Entam,oeba histolytica, from the stool of an acute 



case of entamoebic dysentery. Note the reticulated structure of 

 the cytoplasm and the scanty chromatin in the ring-form nucleus. 



6. The "tetragena" type of motile Entamoeba histolytica, from a chronic 



case of entamoebic dysentery. Note the structure of the nucleus. 

 It contains a heavier peripheral ring of chromatin — a part of 

 which is detached from the nuclear membrane — than in the typical 

 histolytica; and there is a central karyosome, consisting of a 

 central granule surrounded by a circle of chromatin granules. 



7. The preencysted stage of Entamoeba histolytica, from a "carrier" 



case. Note the small size, dense cytoplasm, and heavy peripheral 

 ring of chromatin in the nucleus, which causes it to resemble a 

 small Entamoeba coli. 



8. Encysted form of Entamoeba histolytica, from a convalescent case 



of entamoebic dysentery. Note the small size, the cyst wall, the 

 4 ring-form nuclei, and the "chromidial body." 



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