" BACKGROUND OF DARWINISM—THE WEB OF LIFE 215 
valley.” It must be noted, however, that Drummond did not prove 
his case with sufficient precision, and there is, as Escherich points out 
in his beautiful study of termites, this difficulty, that, while the cast- 
ings of earthworms are soft and loose, the earth-tubes and construc- 
tions of termites are stony. 
Escherich does, however, admit that the termites have some 
agricultural importance, and he points out that there are other serv- 
ices to be put to the credit side of their account. They prune off 
wood that has begun to go; they destroy rotting things, including the 
bodies of small animals; they make for cleanliness and health. In 
some low-lying tracts, as Silvestri has shown, there are dry stretches, 
“termite islands,’ which have been gradually built up from the 
broken-down remains of termitaries. Nor should it be forgotten that 
the white ants are often used as food. On the other hand, Escherich 
does not hesitate to rank them as among the great hindrances to the 
spread of civilisation. They insidiously devour everything wooden, 
from the telegraph-post to the wooden butt of the gun hanging against 
the wall, from books in the library to corks in the cellar. There does 
not seem sufficiently precise information in regard to the living plants’ 
that they attack, and no safe general statement can be made except 
that their appetite is large and catholic. 
With a centre in earthworms, what a variety of interests must be 
included within the radius of their life and work !—centipedes, birds, 
moles, seedlings, man. The same is true of termites, and two further 
illustrations may be given. Observers have reported about thirty 
different species of termites with the habit of feeding on fungi grown 
within the termitary on specially constructed mazy beds. The habit 
is interesting in many ways; for instance, because the fungi afford 
‘a supply of nitrogenous material which is scarce in the ordinary diet 
of wood, and also because a similar habit occurs in the quite unrelated 
true ants. Finally, the web is illustrated by the numerous boarders, 
mostly beetles, that are found in the termitaries—not hostile intruders 
or parasites, but guests which are fed and cared for apparently for the 
sake of a palatable exudation with a pleasant, narcotising effect on the 
termites. With a centre in termites, what a variety of interests must 
we not include within the radius of their life and work!—fungi and 
trees, beetles and birds, lizards and anteaters, and man more than any. 
The hand of life upon the earth.—The hand of life has been 
working upon the earth for untold ages. Take plants, for instance. 
The seaweeds lessen the force of the waves, the lichens eat into the 
