176 THE KINGDOM OF MAN 



seriously attacked by sleeping sickness, as is that of 

 Uganda, as many as 28 per cent, of the people have 

 trypanosomes in their blood. 



There is no ground at present known for distin- 

 guishing Button's T. Gambiense of human blood from 

 that which Bruce has found to be so terribly abundant 

 in Uganda, and to be the cause of sleeping sickness. 

 Indeed all the trypanosomes of the blood of the larger 

 mammalia are singularly alike in appearance ; and the 

 figure which is here given (fig. 50) of the trypanosome 

 of sleeping sickness (T. Gambiense) might quite well 

 serve to represent the T. Evansii of surra disease, the 



Trypanosome Gambiense, from the 

 blood of men suffering from the early 

 symptoms of sleeping sickness. A, 

 after Bruce and Navarro; B, after 

 Castellani. They show a large oval 

 nucleus (drawn as a black mass), and 

 a small black " micronucleus," or 

 " blepharoplast " in front. 



T. Brucfi of nagana disease, or the T. equimim of the South 

 American mal de caderas. 



A most characteristic feature, which has been made 

 out by the careful study of these trypanosomes by means 

 of colouring reagents and very high powers of the 

 microscope, is that, whilst there is a large granular 

 nucleus there is also a small body at the anterior end 

 of the animalcul'e which readily stains and is placed at 

 the end of the root (so to speak) of the vibratile 

 flagellum or free thread. This smaller nucleus has been 

 variously called the " micronucleus," the " centrosome," 

 and the " blepharoplast." It is identical with a structure 



