200 PARASITOLOGY. 



When these swelHng-s are incised a serum escapes in 

 which the protozoa can be found. 



Trypanosoma Brucii (Bruce). 



Distribution. — Found in Africa. 



Description. — The Trypanosoma Brucii are elon- 

 gated and more pointed at the flagellated end ; the body- 

 is slightly curved ; the nucleus is located in the center, 

 close to the surface; the centrosome is in the blunt 

 end and is clearly separated from the flagellum. The 

 flagellum proceeds from this end, follows the entire 

 length of the body, and projects a distance out from 

 the extremity, forming a hair-like appendage as in the 

 preceding species. The protozoon measures about 

 twenty-eight microns in length by one-half to two 

 microns wide; if a drop of blood be drawn they can 

 be found actively moving about in it. 



Life Cycle. — The protozoon divides by simple cell 

 division; the centrosome becomes larger and elong- 

 ated, then divides into two ; the flagellum becomes 

 thickened and divides likewise into two ; this is ac- 

 companied by a like division of the nucleus. The 

 newly formed centrosome, nucleus and flagellum find 

 their way to their respective sides; then comes the 

 division of the protoplasm lengthwise. The two 

 newly formed parasites now develop to full size and 

 again divide. 



Intermediate Host. — The Glossina Morsitans or 

 tsetse fly is the transmitter of the protozoon. 



Animals Infested. — The horse, ass, mule, ox and 

 dog. 



Parts hifested. — Found free in the blood. 



Disease Produced. — Nagana ; tsetse fly disease. 



