THE EARTHWORM 409 



through it. In dry weather they always burrow deeply beneath the 

 surface in order to secure a constant supply of moisture. If they 

 are placed in the sun, or on dusty ground, they very quickly die. 



At night we may see the worms seize dead leaves and carry 

 them partly underground. We must often have seen a number of 

 these leaves partly projecting from their holes. 



The worms feed upon the leaves which they thus secure. It is 

 not easy to see the mouth of a worm, for it is completely covered 

 by the lip when not actually in use. But it is quite large enough 

 to nibble away at the edges of a leaf; and in this way the worm 

 obtains a considerable proportion of its food. 



But it also feeds in another and a perfectly different manner, and 

 one that is very remarkable, for it swallows a quantity of earth, 

 and, after digesting any particles of animal or vegetable matter 

 which it contains, passes it out of its body again in the form of the 

 " worm-casts " with which we must all be familiar. 



This earth, when it issues from the body of the worm, has 

 been transformed into a very powerful manure. So strong is it, 

 indeed, that if a plant is placed in a flower-pot filled with nothing 

 else, it will very quickly die. If a gardener uses it he always mixes 

 it with a quantity of other earth. When spread over the surface 

 of the ground, however, this natural manure is extremely useful, 

 more especially in pasture land, which is seldom manured in the 

 ordinary way. This is done by the wind and the rain. When 

 the worm-casts are thrown up, the wind and rain quickly spread 

 them over the ground, so that the vegetation is kept constantly 

 nourished. 



In fields wherein worms are numerous, nearly a fifth of an inch 

 of rich manure is thus supplied and distributed over the whole 

 surface in the course of a single year. And it is the more valuable 

 for this reason, that the earth of which it is chiefly composed has 

 been brought up by the worms from below. 



Thus we see that the whole of the surface soil is continually 

 passing through the bodies of worms, and continually being re- 

 newed. By earthworms, in fact, the soil is in a sense made, and by 

 earthworms it is constantly kept in a condition which renders it 

 suitable for agricultural purposes. 



