Quote 13
As they circled about, snarling, ears laid back, keenly watchful for the advantage, the scene came to Buck with a sense of familiarity. He seemed to remember it all,--the white woods, and earth, and moonlight, and the thrill of battle...To Buck it was nothing new or strange, this scene of old time. It was as though it had always been, the wonted way of things. (3.37)
Although the adjustment to his new life was at first difficult, Buck begins to recognize that he belongs to the natural world more than he did to the ranch in California.
Quote 14
Buck stood and looked on, the successful champion, the dominant primordial beast who had made his kill and found it good. (3.42)
In killing, Buck established himself as a truly primitive creature.
Quote 15
Far more potent were the memories of his heredity that gave things he had never seen before a seeming familiarity; the instincts (which were but the memories of his ancestors become habits) which had lapsed in later days, and still later, in him, quickened and become alive again. (4.23)
Buck is revitalized by his instincts and his memories of the past. They help him adapt to the new surroundings.