352 THE BOOK OF A NATURALIST 
ments amidst the interlacing fibrous roots of the 
close turf. In the hollow places between the hills, 
where a deeper soil has been formed, the worms 
attain to their full size—all which goes to show 
that chalk itself is not inimical to worms. In 
heavy clays the appearance of the worms show that 
the conditions are not favourable. 
Thus we see that earthworms are perpetually 
invading and peopling all soils, good and bad; 
also that if you have a piece of hard ground barren 
of food for worms and free of worms, where for 
long years they have not been permitted to exist, 
they will constantly flow in from all the surrounding 
rich soils where worms abound and flourish in order 
to get possession of it. The cause, I take it, is that 
the earthworm abhors the soil frequented by other 
worms, which is impregnated with the acid the 
worm secretes and discharges into the soil. The 
acid spoils the ground for him, and he prefers to go 
outside into the most barren and unsuitable places 
to remaining in it. And the perpetual desire 
to get away and seek pastures new is the reason 
of the wide distribution of the earthworm, of its 
universality, so that there is not a clod on the 
surface of the earth without a worm for inhabitant. 
Three or four days after witnessing the remark- 
able phenemenon I described some pages back— 
the rush of hungry earthworms to secure a windfall 
of leaves torn before their time from the trees and 
consequently not well suited to their masticating 
powers—I paid a visit at a country-house a few miles 
