450 THE ROLL OF THE SEASONS 



for the signs of their digging, but when they are found 

 they are more striking than the work of the mole. 

 The soil is brought up from even greater depths, and 

 it is more finely treated, even predigested for the use 

 of the plants. Darwin has estimated for us the 

 amount of the earth-worms' digging, and has told us 

 that in ten years every particle of the field is renewed 

 from below. If it were not for the worms, surely we 

 should have to give our grass fields a double digging 

 every five years, whereas our old pasture of a hundred 

 years' undisturbed grass is the pride of the English 

 grazier. 



There is an object-lesson at work in one or two 

 town museums of nature study that might well have 

 a place in every village school to show more strikingly 

 than by the light of statistics the great work of the 

 earth-worm. A glass jar is filled half-way up with 

 light-coloured sand, on the top of which is an equal 

 layer of leaf-mould or garden-loam. Then, in the 

 presence of the class, half a dozen earth-worms are 

 added and the date of the transaction affixed to the 

 jar. In a very short time streaks of sand run up 

 through the mould and streaks of mould run down 

 through the sand, and before a month has well passed 

 the two ingredients of the jar are as well mixed as 

 though a cook had stirred them. Yet the six-inch 

 jar with a half-dozen worms is not a very exaggerated 

 sample of the average field. We can dig nowhere 

 without coming upon either the worm itself or the 

 burrows from which it has eaten the soil and ejected 

 it at the surface in finely masticated form. On a 

 favourable night a few weeks hence you may see every- 

 where the foot-long forms of full-grown earth-worms 



