All this while the Pup was growing, as perhaps no harbor seal of his months had grown before. When spring came, he saw less of Captain Ephraim, but he had compensation, for the good captain now diverted into his modest grounds a no-account little brook which was going begging, and dug a snug little basin at the foot of the garden for the Pup to disport himself therein. All through the summer he continued to grow and was happy, playing with Toby, offending the yellow cat, amusing Miss Libby, and affording food for speculation to Mrs. Barnes over her knitting. In the winter Captain Ephraim polished him up in his old tricks, and taught him some new ones. But by this time he had grown so big that Mrs. Barnes began to grumble at him for taking up too much room. He was, as ever, a model of confiding amiability, in spite of his ample jaws and formidable teeth. But one day toward spring he showed that this good nature of his would not stand the test of seeing a friend ill-used. It happened in this way. Toby, who was an impudent little dog, had managed to incur the enmity of a vicious half-breed mastiff, which lived on a farm some distance out of Eastport. The brute was known to have killed several smaller dogs; so whenever he passed the Barnes' gate, and snarled his threats at Toby, Toby would content himself with a scornful growl from the doorstep. But one morning, as the big mongrel went by at the tail of his master's sled, Toby chanced to be very busy in the snow near the gate digging up a precious buried bone. The big dog crept up on tiptoe, and went over the gate with a scrambling bound. Toby had just time to lift his shaggy little head out of the snow and turn to face the assault. His heart was great, and there was no terror in the growl with which he darted under the foe's huge body and sank his teeth strategically into the nearest hind paw. But the life would have been crushed out of him in half a minute, had not the Pup, at this critical juncture, come flopping up awkwardly to see how his little friend was faring. Now the Pup, as we have seen, was simply overflowing with good-will towards dogs, and cats, and every one. But that was because he thought they were all friendly. He was amazed to find here a dog that seemed unfriendly. Then all at once he realized that something very serious was happening to his playmate. His eyes reddened and blazed; and with one mighty lunge he flung himself forward upon the enemy. With that terrific speed of action which could snap up a darting mackerel, he caught the mastiff in the neck, close behind the jaw. His teeth were built to hold the writhings of the biggest salmon, and his grip was that of a bulldog--except that it cut far deeper.