530 



PROTOZOA 



opposite part of the periphery. This smaller body stains more intensely 

 than the larger one, while the cytoplasm of the parasite stains very 

 dimly, sometimes showing only a faint peripheral rim. Any nuclear 

 and cytoplasmic staining methods will bring out these points in Zenker 

 fixed material. Smears stain well by Wright or the Nocht-Roman- 

 owsky method. The large cells containing the parasites are supposed 

 by Christopher to be the endothelial cells from the finest capillaries. 

 Leishman, Marchand, Rogers and others think the bodies one stage 

 in the life cycle of a flagellate, possibly a trypanosome, Rogers arid 

 Marchand having seen flagellates develop from infected tissue in vitro 

 in non-coagulable blood. Donovan, however, claims to have found 

 small forms in the red blood cells in the peripheral circulation when 



FIG. 162 



Protozoa in a case of tropical ulcer. Smear preparation from the lesion stained with Wright's 

 Romanowsky blood-staining fluid. The ring-like bodies with white central portions and containing 

 a larger and a smaller dark mass are the micro-organisms. The dark masses in the bodies are 

 stained a lilac color, while the peripheral portions of the bodies in typical instances are stained a 

 pale robin's-egg blue. The very dark masses are nuclei of cells of the lesion. X 1500 approximately. 

 (After Wright.) 



the temperature was above 103, and his observation has been con- 

 firmed by Lave ran and Mesnil, who believe the organism to be a piro- 

 plasma. Segregation is recommended as the best means of eradicating 

 the disease. 



Rabies (Hydrophobia). 



Rabies is an acute disease of animals, dependent upon a specific 

 virus, and communicated by inoculation to man. It is usually associated 

 with an injury, such as the bite of a dog, or the inoculation of the 

 broken surface with the saliva of an animal affected with the disease. 



