to custom,—­and as he stretched his four hairy paws out comfortably, and blinked his brown eyes at a portly blackbird prodding in the turf for a worm within a stone’s throw of him, he was evidently considering whether it would be worth his while, as an epicurean animal, to escort these two men on their usual round on such a warm pleasant morning.  For it was a dog’s real lazy day,—­a day when merely to lie on the grass was sufficient satisfaction for the canine mind.  And Nebbie, yawning extensively, and stretching himself a little more, closed his eyes in a rapture of peace, and stirred his tail slightly with one, two, three mild taps on the soft grass, when a sudden clear whistle caused him to spring up with every hair bristling on end, fore-paws well forward and eyes wide open.

“Nebbie!  Nebbie!”

Nebbie was nothing if not thoroughbred, and the voice of his master was, despite all considerations of sleep and sunshine, to him as the voice of the commanding officer to a subaltern.  He was off like a shot at a tearing pace, nose down and tail erect, and in less than a minute had scented Walden in the shrubbery, which led by devious windings down from the orchard to the banks of the river Rest, and there finding him, started frantically gambolling round and round him, as though years had parted man and dog from one another, instead of the brief space of an hour.  Walden was smiling to himself, and his countenance was extremely pleasant.  Nebbie, with the quaint conceit common to pet animals, imagined that the smile was produced specially for him, and continued his wild jumps and barks till his red tongue hung a couple of inches out of his mouth with excess of heat and enthusiasm.

“Nebbie!  Nebbie!” said the Reverend John, mildly; “Don’t make such a noise!  Down, lad, down!”

Nebbie subsided, and on reaching the river bank, squatted on his haunches, with his tongue still lolling out, while he watched his master step on a small floating pier attached by iron chains and posts to the land, and bend therefrom over into the clear water, looking anxiously downward to a spot he well knew, where hundreds of rare water-lilies were planted deep in the bed of the stream.

“Nymphea Odorata,”—­he murmured, in the yearning tone of a lover addressing his beloved;—­“Nymphea Chromatella—­now I wonder if I shall see anything of them this year!  The Aurora Caroliniana must have been eaten up by water-rats!”

Nebbie uttered a short bark.  The faintest whisper of ‘rats’ seriously affected his nerves.  He could have told his master many a harrowing story of those mischievous creatures swimming to and fro in the peaceful flood, tearing with their sharp teeth at the lily roots, and making a horrible havoc of all the most perfect buds of promise.  The river Rest itself was so clear and bright that it was difficult to associate rats with its silver flowing,—­yet rats there were, hiding among the osiers and sedges, frightening the moorhens and reed-warblers out of their little innocent lives.  Nebbie caught and killed them whenever he could,—­but he had no particular taste for swimming, and he was on rather ‘strained relations’ with a pair of swans who, with a brood of cygnets kept fierce guard on the opposite bank against all unwelcome intrusion.