36 SOME MINUTE ANIMAL PARASITES 



danger, for it is from that region that thousands of 

 coolies are imported to work rubber plantations both 

 in Africa and in Malay. After a short period, often 

 only of about six months' duration, the coolies con- 

 sider that they have " got rich," and insist on 

 repatriating themselves. They return to their native 

 land, and more than one may carry away the begin- 

 nings of insidious diseases. Consequently, the 

 Indian authorities exercise great care in preventing 

 infected persons from landing, and in scrutinizing 

 certain kinds of vegetable cargo for possible pupae of 

 Glossina palpalis. A Glossina, G. tachinoides, is also 

 known in Arabia. 



Unfortunately, the seriousness of affairs was not 

 realized in time, for another kind of sleeping sick- 

 ness has comparatively recently been discovered in 

 Rhodesia, and has already claimed its toll of 

 European victims. Again, too much attention may 

 be said to have been focussed on G. palpalis as the 

 carrier of disease. G. palpalis is not found in all the 

 areas where sleeping sickness occurs, nor is it 

 certain that Trypanosoma gambiense is conveyed from 

 man to man by G. palpalis alone. In fact, evidence 

 is accumulating to show that some other biting 

 insect, probably also a Glossina, may occasionally 

 transmit the parasite by its bite. In Rhodesia, at any 

 rate in parts, G. palpalis is unknown, but two nearly 

 allied Glossinae, G. morsitans and G. fusca, are present 

 in large numbers, and these flies are known to bite 

 both man and beast. 



Recently (1910) a young Englishman arrived at 

 Liverpool suffering from a form of sleeping sickness, 



