The Call of the Wild
How we cite our quotes:
To Buck's surprise these dogs manifested no jealousy toward him. They seemed to share the kindliness and largeness of John Thornton. As Buck grew stronger they enticed him into all sorts of ridiculous games, in which Thornton himself could not forbear to join; and in this fashion Buck romped through his convalescence and into a new existence. (6.3)
Buck softens his defenses after he is rescued from his hard life on the trail. He adapts once again, this time to a new environment and a new set of rules.
But in the end Buck's pertinacity was rewarded; for the wolf, finding that no harm was intended, finally sniffed noses with him. Then they became friendly, and played about in the nervous, half- coy way with which fierce beasts belie their fierceness. (7.15)
Buck reverses roles, initiating friendship with the wolf the way other dogs initiated friendship with him.
One wolf, long and lean and gray, advanced cautiously, in a friendly manner, and Buck recognized the wild brother with whom he had run for a night and a day. He was whining softly, and, as Buck whined, they touched noses. (7.45)
London uses the word "brother" to emphasize a different connection between Buck and the wild wolf than between Buck and the other dogs.