Amebic Dysentery 639 



EXPLANATION OF FIG. 260 



(AH figures drawn by Charles F. Craig, M. D.) 



I. Upper Group. — Enlamceba coli stained with Giemsa stain. 



A,B, and C. Vegetative organisms showing nuclear membrane, karyosome, 

 and collections of chromatin upon the nuclear membrane and within the 

 hyaloplasm.' Vacuoles are also present. 



D. An organism containing a protozoan parasite which might be mistaken 



for spores. 

 H. Division of nucleus (primitive mitosis). 



E. Partially divided ameba containing two nuclei. 



F. G. Ameba resulting from simple division. 



M. Schizogony of Entamoeba coli. Eight daughter nuclei in vegetative 



form. 

 N. Ameba resulting from schizogony. 

 I. Earliest stage in cyst formation. Cytoplasm clear of foreign bodies and 



nucleus showing collection of chromidial masses upon the inner side of 



the nuclear membrane. 

 K, L, O, P. Two- and four-nucleated stage of reproduction within the cyst. 

 Q. Encysted form containing two large nuclei and a mass of chromatin, 

 R. Fully developed cyst of Entamoeba coli containing eight nuclei. 

 Lower Group. — Eniamosba coli, fixed in sublimate alcohol and stained with Dela- 

 field's hematoxylin. Note the more delicate staining of the nucleus and 



the greater detail obtained with this method of staining. 

 A, B, C. Vegetative amebas showing variations in the structure of the 



nucleus. 

 A An organism during schizogony, containing eight nuclei. 



E. Mitotic division of the nucleus as observed in this species. 



F. A fully developed cyst of Entamoeba coli containing eight daughter 



nuclei. 



G. The four-nucleated cystic stage of Entamoeba coli sometimes mistaken 



for the cyst of Entamoeba tetragena. 



H. Two-nucleated cyst of Entamoeba coli. 



I. Young amebffi originating from the cysts of Entamoeba coli. 



K. Fully developed cyst in which the cystic membrane is apparently absent. 



L. Degenerated cyst of Entamoeba coli, filled with vacuoles, and containing 

 masses of chromatin. No nucleus is visible. 

 II. Entamceba histolytica stained with Giemsa stain. 



A. Organism showing distinction between the ectoplasm and endoplasm, 

 nucleus and vacuole. 

 B. Organism showing vacuole and red blood corpuscle and nucleus contain- 

 ing minute karyosome and chromatin dots in the hyaloplasm. 



C. Organism showing nucleus and numerous red blood corpuscles. 



D. Organism in first stage of nuclear division, showing division of the karyo- 



some and minute dots of chromatin in hyaloplasm. 



E. Organism showing later stage of nuclear division, the polar bodies being 



connected by a filament of chromatic substance. 



F. First stage of formation of spore cysts; the nucleus distributing chro- 



matin to the cytoplasm. 



G to /. Stages in the process of formation of spore cysts, the chromatin being 

 distributed to the cytoplasm and collected in threads or masses, 

 while the nucleus is observed as a flattened body crowded against the 

 periphery of the parasite. 



L. Degenerated parasite containing vacuoles and free chromatin. 



K, M, N. Entamceba histolytica in the final stage of the formation of spore 

 cysts. The free chromatin has collected at the periphery, and sur- 

 rounded by a small amount of cytoplasm, is being budded off from the 

 parent organism. 



0. Degenerated organism filled with vacuoles and free from chromatin. 

 The nucleus stains abnormally and there is no distinction between the 

 ectoplasm and endoplasm. 



P. Entamceba histolytica filled with erthyrocytes, the nucleus being crowded 

 to the periphery and staining abnormally (Charles F. Craig, M. D., 

 in Journal of Medical Research, vol. xxvi. No. i, April, 1912). 



