THE WEB OP LIFE 59 



the idea of which is essential to an understanding 

 of the struggle for e?:istence and natural selection. 

 But it also illustrates what Darwin had learned 

 from Lyell — that great results may be brought 

 about by the accumulation of infinitesimal items. 

 As Prof. A. Milnes Marshall said : " The lesson 

 to be derived from Darwin's life and work cannot 

 be better expressed than as the cumulative import- 

 ance of infinitely little things." 



Termites, or White Ants. — ^Henry Drummond, 

 in his " Tropical Africa," tried to make out a case 

 for the agricultural importance of termites, or 

 white ants. It is well known that these old- 

 fashioned insects have a pruning action in the 

 forest, destroying dead wood with great rapidity. 

 Houses and furniture, fences and boxes, as well 

 as forest-trees, fall under their jaws. In some 

 places, " if a man lay down to sleep with a wooden 

 leg, it would be a heap of sawdust in the morning." 

 But what of the termites' agricultural importance ? 

 The point is that they keep the soil circulating 

 by constructing earthen tunnels up the sides of 

 trees and posts and by making huge obelisk-hke 

 ant-hills, or termitaries. " The earth-tubes crumble 

 to dust, which is scattered by the wind ; the rains 

 lash the forests and soils with fury, and wash ofi 

 the loosened grains to swell the alluvium of a 

 distant valley." It must be noted, however, 

 that Drummond did not prove his case with suffi- 

 cient precision, and there is, as Escherich points 

 out in his beautiful study of termites,' this difficulty, 

 that, while the castings of earthworms are soft 

 and loose, the earth-tubes and constructions of 

 termites are stony. 



» " Die Termiten." (Leipzig, 1909.) 



