Where the brook passes under a bridge of some size the current divides to go through several small arches. There is here some fall, and the stream is swift and bright, chafing round and bubbling over stones. Here the `miller's thumbs' are numerous--a bottom fish growing to about four inches in length, and with a head enormously broad and large in proportion to its body. They rarely rise from the mud or sand; they hide behind stones, their heads buried in the sand, but their tails in sight. Every now and then they change positions, swimming swiftly over the bottom to another spot. Their voracity is very great, and they often disappoint the angler by taking his bait. The cottage people are said to eat them. The `stwun loach'--stone loach, as the lads call it--hides also behind and under stones, and may be caught by hand. These loach are apparently capricious in their habits; certain spots abound with them, in others you may search the stream in vain for a long distance. So, too, with the gudgeon: I noticed in one brook I frequently passed that they never came up beyond one particular bend, though there was no apparent difference in the soil or in the stream itself. In the brook the jack do not seem to care much about them; but in the lake above there are no gudgeon, and there a gudgeon is a fatal bait. Nothing is so certain to take; the gudgeon will tempt the pike there when an ordinary roach may be displayed before him without the slightest effect. A flood which brings down a large quantity of suspended mud and sand discolouring the water attracts the fish: they are looking for food. But too much mud compels them to shift their quarters. This is well known to those who net the stream. They stretch the net across the brook a few yards below a bridge or short culvert--places much haunted by fish. Then the bottom of the stream above the culvert is thoroughly stirred up with a pole till the water is thick with mud, and this, passing through the culvert (where the pole cannot be used and the fish would otherwise be safe), forces them to descend the stream and enter the net. Probably they attempt to swim up stream first, but are deterred by the pole thrust under the water, and then go down. It is said that even eels, who like mud, will move if the volume of mud sent through is thick enough and continued sufficiently long. The fact that a little stirring of the bottom attracts fish is made use of along the Thames to attract bait for those night-lines which are the detestation of the true angler. The bait catcher has a long pole, at the end of which are iron teeth like a rake. With this he rakes up the mud, waits a few seconds, and then casts a net, which generally brings some minnows or other small fish to shore. These fish are then placed in a bucket, and finally go on the night-lines.