Field-Labourers 85 



temporary purposes, only they crumble into dust after 

 a little exposure. But the dust, brought up from the 

 sub-soil in the first instance and now returned to earth 

 again or scattered abroad by the wind, has been altered 

 in character ; it has been powdered for one thing, and 

 it has been to some extent mixed with animal juices for 

 another, since the only ' mortar ' at the termite's 

 command is its own saliva, by means of which it makes 

 the grains adhere together. So far, then, the soil which 

 the termite has brought up from below is richer than 

 before ; but the chief point gained seems to be that the 

 soil is being constantly turned over and over. 



Some districts are more especially favourable to the 

 termite than others, and in one of these there are miles 

 of trees all covered with its earthworks. * The soil of 

 the tropics is therefore in a state of perpetual motion. 

 Instead of the upper crust being converted into a paste 

 by the autumn rain and then baked to adamant, the 

 under soil being hermetically sealed up from light and 

 air, there is a slow constant transference, grain by 

 grain.' 



But the tunnels do not represent nearly all the 

 termite's work, though they are much. Besides these, 

 there are the nests, mounds of earth of huge size, 

 which are a common feature of the African landscape, 

 and can be seen for miles. In India they are seldom 

 more than a couple of feet or so in height, but in 

 Central Africa they are from ten to seventeen feet high 

 and contain many tons of earth, while the excavations 

 beneath are many feet and even yards deep. 



The mounds are not solid, but composed of many 

 tunnels, chambers, and galleries, yet they are so strong 

 that they will bear the weight of a man on horseback 



