SOIL OR SURFACE-MATTER. 231 



vegetable decay, but also to the worm-work. When 

 the soil becomes rich, the earthworms do a greater 

 amount of work, but while it remains poor they can 

 do little or none, owing to the paucity of their num- 

 ber ; so that to vegetable decay is principally due 

 the growth of the first mould. 



Lands with a permanent turf or sod, that has 

 remained untilled for ages, may be used either as 

 pasture or as meadow land. If the surface-soil 

 were due only to the earthworms, then in a field all 

 of which has the same fertility, subsoil, &c., if a part 

 is used as permanent pasture, while from the rest 

 hay is always cut, the condition of the whole ought 

 to be uniform, and over all there would be a gradual 

 increase of the mould. This, however, is well known 

 to the farmer not to be the case ; for the mould will 

 increase on the pasture-land, but not on the per- 

 manent meadow, unless the latter is cut early enough 

 to allow of a second growth or " after-grass," which 

 is left to rot on the ground. And in corroboration 

 of this principle, all farmers state that machine- 

 mowing is more severe on meadow-land than hand- 

 mowing, because the latter does not or cannot cut 

 as close as the former ; for similar reasons horses 

 are harder on grass-land than either sheep or cows. 

 To counteract the injurious effect of removing from 

 the meadow-land all the vegetation which would 

 naturally decay on it, the land has to be topdressed 



