8 GEOGEAPHICAL DISTEIBUTIOK 



occurs, for instance, throughout the Congo-basin, the Congo and 

 its affluents are coloured red ; but, for the reasons ah-eady 

 stated — apart from the fact that a species of Glossina is not 

 necessarily to be found all through the year at a spot at which 

 it may be known to exist — it must not be imagined that G. pal- 

 palis occurs continuously over the whole of the Congo River 

 system. The present map should only be considered as indi- 

 cating, very roughly, how large a portion of Africa is included 

 within the area of distribution of the genus Glossina, and con- 

 sequently exposed to the contingent perils. 



