337 



6. Examine from day to day, and make sub- 

 cultures when a good growth is got (in about a week). 



Trypanosomes in cultures are generally small, 

 5 to 15^, but may be much larger, and they nearly 

 always are of the Herpetomonas (p. 362) form. 



I. T. gambiense. The cause of sleeping sickness 

 or better human trypanosomiasis, a disease of tropical 

 Africa. It is stated that native dogs (in Uganda) also 

 harbour the parasite. 



Incubation Period. Is not easy of determination, 

 but can last months and probably years. 



Symptoms. (i) A general polyadenitis, i.e., en- 

 largement of the lymphatic glands, especially the 

 cervical. (They may in some cases decrease again in size.) 



(2) Fever of an irregular remittent character, but 

 frequently at first taking the form of an evening! rise 

 followed by a fall in the morning. 



(3) Acceleration of the pulse and rate of breathing. 



(4) Skin lesions ; patches of erythema, e.g., on 

 the thorax, with congestion and some oedema giving a 

 purplish appearance. A papulo-vesicular eruption is 

 also common, especially in the native. 



(5) Oedema ; especially of the face, giving a puffy 

 look, also on the legs and elsewhere. 



(6) Nervous symptoms ; first perceived, perhaps, as 

 a mere alteration of expression or disposition. These 

 eventually show themselves in headache, unsteady gait, 

 tongue tremors, tremor of the outstretched hand, 

 commencing apathy, disposition to sleep, lethargy, 

 coma, death. Occasionally ' sleep symptoms ' are 

 entirely absent. 



I. Blood Examination. Parasites may be absent 

 from the^ peripheral blood for a month or more at a 

 time, and even if abundant, seventy to a cover-slip, 

 may again completely disappear. The number of 



