ORGANIC ADAPTATION 



341 



To cerebrospinal fluid 

 Causing sleeping sickness and death. 



Trypanosomes 

 in human blood 

 causing Trypanosome fever 



Transmission by 

 bite of tsetse fly : 



Man, Antelope, etc. 



Tsetse Fly 



Transmission by 

 bite of tsetse fly 



orms in salivary glands 

 ready for re-infection 

 (20th-30thday) 



Crithldlal forms In 



salivary glands 



(2 or 3 days later) 



Forms in mid gut 

 (43 hrs. after infective meal) 



Kewly arrived form 

 in salivary gland 

 (12th to 20th days) 



Long, slender forms in proventrlculus 

 (about 10th to 15th days) 



Fig. 224. — Life history of the Trypanosome, Trypanosoma gambiense, 

 that produces African Sleeping Sickness in Man. Magnified about 1500 times. 

 (Modified, after Chandler.) 



