26 REPORT OF THE HARVARD AFRICAN EXPEDITION 
necessary to obtain from water holes sometimes used by animals as drinking 
places. 
It will be obvious that, from the standpoint of hygiene and sanitation, cer- 
tain of the geographical features of the situation of the coast cities and towns, 
and the lagoons, tidal creeks and swampy areas about them constitute problems 
of great magnitude in reference to the control of insect-borne disease. It is also 
obvious that the geographical features of the interior suggest that it has a 
more salubrious climate than the coast. 

