SHORTER ARTICLES AND DISCUSSION 



NOTES ON THE GEOLOGIC WORK OF TERMITES IN 

 THE BELGIAN CONGO, AFRICA 



The following notes were taken during 1911 in the region 

 about seventy-five miles west of Lake Tanganyika between lati- 

 tudes 4° 15' and 5° south. This region lies along the western 

 base of the great mountain system which passes to the west of 

 Lake Tanganyika. 



The Loami River Region. — The gentle slope between the base 

 of the mountain and the swamp of the Loami river is pretty 

 generally covered with termites' nests averaging about ten feet 

 in height and forty feet in diameter at the base. Some of the 

 mounds are much larger, but they are generally composed of 

 two nests which were started so close together as to grow into 

 one mound. They are very much rounded by weathering, but 

 a few of them have newly formed pinnacles projecting from 



In many well-drained places as many as five hills to the acre 

 may be counted, but this is more than are ordinarily found. 

 One may walk for three or four hours, however, through country 

 averaging more than one nest to the acre. The most favorable 

 places for the nests seem to be where the soil is deep and well 

 drained. 



Methods of Construction. — The newest nests recognized were 

 small slightly raised mounds about three feet in diameter with 

 two or three small chimney-like pinnacles rising from them. 

 Before there was anything to attract attention above the surface 

 of the ground, the termites had made a nest below the surface 

 and had mixed the surrounding soil with excrement from their 

 bodies to form a stiff clay. From this base, they then built 

 small chimneys about a foot in diameter, with passages about 

 two inches in diameter leading from the nest. It is up through 

 these openings that the mounds are built, the small white ants 

 carrying up little balls of soft clay and plastering them around 

 the tops of the chimneys. This is the only work in which I have 

 seen the workers expose themselves to the sunlight. 



The chimneys are continually being washed down by the 

 storms, forming large rounded mounds with passageways about 

 two inches in diameter leading through them and down below 

 the surface of the ground. These passageways are enlarged at 

 irregular intervals into spherical chambers about four inches 

 429 



