332 EASTERN ETHIOPIA xxvn 



convert straw and wood into this red material. Hayes 

 is strongly of opinion that much of the mud carried 

 down by the Nile is due to the activity of termites 

 in the western borderland of Abyssinia. 



Drummond, in an interesting essay on termites, 

 gives an account of the ravages committed by these 

 insects on the trees of the great plateau between Lakes 

 Nyasa and Tanganyika ; he also draws attention to the 

 enormous amount of earth which is removed by the 

 termites from the deeper layers of the soil and brought 

 to the surface for the construction of their nests and for 

 covering the bark of trees. During the dry season 

 this work goes on incessantly, and much of it becomes 

 distributed by the wind as dust, and serves as a 

 top-dressing to the vegetation around. In the rainy 

 season, which lasts intermittently for weeks, the loose 

 soil is washed away in quantities, and some of the 

 termitaria, though they have great resisting powers, are 

 not invulnerable, and ultimately succumb to denuding 

 agents such as mud and rain. 



This is an interesting theory and worth consideration, 

 especially when taken in conjunction with Hayes' 

 observation, for he explained to me that the red earth 

 which is such a conspicuous feature of the mud brought 

 down by the Nile, ordinarily described as coming from 

 the Abyssinian Highlands, is not to be seen apart from 

 the districts in which termites abound. 



Termites are blind, but when disturbed they express 

 their alarm by hissing ; it is well established that they 

 have means of communication by sound. The exact 

 mode in which the sound is produced remains unknown. 

 Although termites are blind they can inflict sharp bites 

 with their mandibles. 



In the winged state the termites are much altered in 

 shape and form. They have a pair of eyes, and four 

 wings, but these differ from the wings of most insects, 

 for they are only used for a single flight, and are then 

 shed by detachment at a suture which exists across the 



