The passing of the beast, however, upset the life of the shallow, amber pool. The mud of his digging had no more than cleared away before the under-water creatures of the place, jackals on the lion's spoor, came forward, eager to feast on the remnants of his meal. Bream, sunning themselves on the shallow margins of the other side, give a sinuous swish to their tails and dart up. A yellow perch poises, slips forward a yard, poises again and then thinking the place safe, comes forward for his share. In beauty and intelligence the yellow perch is easily the king of the brook waters and I can but admire his coloring, not only for its beauty but for its protective value. His dark back makes him almost invisible from directly above. Should you get a glimpse of his side you might well think it but the ripple of sunlight and shadow in the water, so well is this simulated by the broad bands of green and yellow which run from the dark back down the sides. It is only when he turns far on his side and gives you a glimpse of red fin and white belly that he is plainly visible, and only desperate need will make him thus turn. After perch and bream have left, satisfied, a little group of thumbling hornpouts come and grub and dabble in the muddy hole whence the unio came, feeding upon I know not what; probably tiny infusoriae of the fresh water. These little black cats are the busiest folk of the brook at this time of the year, and just whence they come or whither they go I cannot say. If you fish the waters with angle worms you will not pull out one of these little fellows till the summer is fairly on. Then, dog days having arrived, you will get a chance to catch nothing else, so long as one of them remains in the pool you choose. They are great angle-worm chasers and will get across a pool and grab a bait before any other denizen of the place can possibly get to it. Their agility is the more surprising when one remembers that the grown hornpout is but a sluggish chap and that they are not built on lines that presage swiftness. You may catch the big horn pouts at any season, but these little chaps are peculiar to the dog days. I have an idea they hibernate in the mud at bottom until warm weather calls them forth, and that by next spring, so voracious is their appetite and such their agility in satisfying it, they are as big as the others of their kind. So eager are these gourmands for bait that if but one is in a pool you may catch him, throw him back and catch him again times without number, provided the hook does not happen to injure his tough jaw.