On approaching one of these places, I find the water to be apparently without inmates. They had only been alarmed by my approach, which, as I had but little time to spare, was not as cautious as it ought to have been. However, I remained perfectly still, and presently a little fish appeared from below. It was soon followed by a second and a third, and before long a whole shoal of fish were floating almost on the surface, looking out for insects which had fallen into the water.
The day being hot, and with scarcely a breath of wind, the fish soon became quite bold. They did not move beyond the small spot in which they had appeared, but they all had their tails in slight movement, and their heads in one direction, thus showing that although the water appeared to be perfectly motionless, there must be a current of some sort, fish always lying with their heads up the stream, so as to allow the water to enter their mouths and pass over their gills.
If then these sluggish streams were unlike those of Oxford, where the ground is low, and nearly level, how utterly distinct must they be from those of hilly and especially of rocky localities!
In the earlier part of the present year I was cursorily examining a brook in Cannock Chase, in Staffordshire. Unfortunately, the day was singularly inauspicious, as the sun was invisible, the atmosphere murky, and a fierce north-east wind was blowing, a wind which affects animals, etc., especially the insect races, even more severely than it does man. Even the birds remain under shelter as long as they can, and not an insect will show itself. Neither, in consequence, will the fish be "on the feed."
On a previous visit, we had been more fortunate, trout, crayfish, etc., testifying to the prolific character of the brook, which in one place is only four or five feet in width, and yet, within fifty yards, it has formed itself into a wide and treacherous marsh, which can only be crossed by jumping from one tussock of grass to another; and yet, again, it suddenly spreads out into a broad and shallow torrent, the water leaping and rippling over the stony bed. Scarcely a bush marks its course, and within a few yards it is quite invisible.
As we shall presently see, the brooks of the chalk downs of Wiltshire, and of the regular mixture of rock and level ground, which are characteristic of Derbyshire, have also their own separate individualities.
We shall, however, find many allusions to them in the course of the work, and we will therefore suppose ourselves to be approaching the bank of any brook that is but little disturbed by man. What will be likely to happen to us will be told in the following chapters.
CHAPTER II.
Life-history of the water-rat—No science can stand alone—What is a water-rat?—The voles of the land and water—Their remarkable teeth—The rodents and their incisor teeth—The tooth and the chisel—The skate "iron"—Chewing the cud—Teeth of the elephant—Feet of the water-vole—A false accusation—Water-voles in gardens—Winter stores—Cats and water-voles—Subterranean pioneering—Mental character of the water-vole—Standing fire—Its mode of eating.