CHAPTER X 



OTHER DISEASES, MOSTLY TROPICAL, 

 KNOWN OR THOUGHT TO BE TRANS- 

 MITTED BY INSECTS 



SLEEPING SICKNESS 



NE of the worst scourges of Africa and 

 one that is to-day attracting world- 

 wide attention is the disease known as 

 trypanosomiasis, the terminal phase of 

 which is sleeping sickness, one of the most ghastly 

 diseases that we know. 



Among the Protozoa referred to in one of the 

 earlier chapters mention was made of certain try- 

 panosomes which inhabit the blood of man and 

 certain animals. Very little was known concerning 

 these parasites previous to the beginning of the 

 present century, but since that time several have 

 been found to be of great economic importance. 

 The group is being studied extensively and every 

 day our knowledge of them is increasing so that 

 we now know quite definitely the life-history of 

 several. 



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