180 Grey Rock and Thyme 



uncanny fascination. A stream is never safe on 

 limestone soil ; and though, from the porousness 

 even of the more solid masses of rock, daylight 

 streams are rare among the higher hills, a brook 

 coming with a light course from miles of less per- 

 meable soil is often trapped and drawn downwards 

 as soon as it strikes the riddled zone. When the 

 stream is an intermittent one, so that for many 

 months of the year its channel is empty and dry, 

 the swallow-hole looks doubly strange. If the rock 

 is overlaid with a thick layer of soil, as often where 

 it first rises from lower ground, the swallow-hole 

 may be at least twenty feet deep, nearly circular 

 in shape, and narrowing inward to the bottom, 

 where the actual orifice is choked by loose earth 

 and leaves. In the long idleness of the drier months 

 the sides of the funnel become sown by ash-seeds 

 and sycamore keys, or threaded by the roots of some 

 overhanging elm, so that saplings have freely 

 sprung, and the hollow is a nursery of well-grown 

 trees, clinging to the circular banks. Ivy hangs 

 about their trunks, with fresh green blossom spring- 

 ing from the brown flood-stain of last year ; and 

 when the October sun falls warmly on the rounded 

 hollow, the wasps suck their last banquet by the 

 nether portals, and the broad red admiral makes 

 sudden sallies into the sun. But the week comes, 

 in every normal winter, when the earth is awash 

 with rain, and the brook that runs modestly under 

 the hedge at the ploughed field's side comes sweep- 

 ing round the thorn-roots in the hedgerow, and 

 crowned with earthy foam. Then the swallow- 



