GLOSSINA MORSITANS IN NORTHERN RHODESIA. 79 



In these shady places the natives are always liable to come into much the same relation 

 to G. morsitans as are natives in palpalis areas to G. palpalis, by repeatedly passing 

 the shady spots where the flies lurk. An infected fly brought into a village of this 

 type or to one of the shady water-holes could easily remain long enough to infect a 

 number of people. The writer does not believe that G. morsitans could ever subsist 

 entirely on man, as it is so rarely that a fly obtains a full meal on a healthy person, 

 European or native, but where domestic animals remain, as in the case of each village 

 mentioned above at the time of the epidemic, the fly might be able to breed actually 

 in this unusual type of village. At any rate the shady and scattered nature of the 

 villages where these local epidemics have occurred seems to indicate their cause. 



The epidemics could probably be avoided by allowing no shade in the villages and 

 by making these compact. Two villages should never be allowed on opposite banks 

 of the temporary streams, nor where stretches of shaded sand are left by the falling 

 of the water. The clearing of the bush around water-holes in these streams however 

 is a difficult problem, as the water would fail if the shade were removed. 



