TRYPANOSOMA GAMBIENSE 21 7 



A large nucleus is always seen, also a centrosome, a small chro- 

 matic mass likewise called a blepharophast near one pole. 



The flagellum is at the anterior extremity; the short pointed end 

 is the posterior extremity. Cell division begins in the nucleus, the 

 cell dividing longitudinally, the centrosome, flagellum, and the 

 protoplasm dividing last. Trypanosomes frequently appear in 

 clumps with the ends united, resembling a wheel. 



The trypanosomes exist in two hosts one a suctorial insect and 

 have a sexual and an asexual existence (alternate generation). 



In an infected owl the organism has been observed clinging fast 

 to the red cells, absorbing nutriment during the day, while at night 

 it swims about freely in the plasma. 



In owl's blood the trypanosome assumes asexual forms, called 

 macro gametes. These macrogametes penetrate the erythrocytes, 

 accumulating the remnants of the red cells in the protoplasm. The 

 nucleus of the trypanosome may be seen in the interior of the pro- 

 toplasm. The microgametocytes arise from the asexual forms and 

 when mature, give rise to eight microgametes. 



TRYPANOSOMA GAMBIENSE. 



Castellani found that this trypanosome is the cause of sleeping 

 disease among the natives of South Africa. The organism has 

 been found in the cerebro-spinal fluid in cases of sleeping-sickness 

 quite uniformly. They have also been found in the blood. The 

 disease has a long period of incubation (months), runs a long course 

 usually, and, at its full development, it is a meningo-encephalo- 

 myelitis. This is characterized by hebetude, somnolence, and 

 coma. These symptoms are accompanied by disturbance of the 

 motor apparatus, oedema, irregular temperature, rapid pulse, 

 emaciation, skin eruptions, and death in coma. In these cases the 

 parasites may be seen in the blood slowly winding their way through 

 the corpuscles. The pathogenic action is due no doubt to some 

 toxin elaborated. 



