- "The law of club and fang." (Chapter 2, title)
The laws of the violent world that Buck has been forced into.
- "When he moaned and sobbed, it was with the pain of living that was of old the pain of his wild fathers, and the fear and mystery of the cold and dark that was to them fear and mystery." (Chapter 3)
Buck howls with the other dogs in Dawson.
- "He was sounding the deeps of his nature, and of the parts of his nature that were deeper than he, going back into the womb of Time." (Chapter 3)
As Buck leads the dog-pack in hunting a rabbit, he feels the first calling of his primordial nature.
- "For the pride of trace and trail was his, and sick unto death, he could not bear that another dog should do his work." (Chapter 4)
Dave's resentment at being taken out of the team, even though he is sick.
- "Love, genuine passionate love, was his for the first time." (Chapter 6)
Buck's experience with John Thornton.
- "He was older than the days he had seen and the breaths he had drawn. He linked the past with the present, and the eternity behind him throbbed through him in a mighty rhythm to which he swayed as the tides and seasons swayed." (Chapter 6)
Buck's link with primordial time, even as he sits by John Thornton's fire.
- "It filled him with a great unrest and strange desires. It caused him to feel a vague, sweet gladness, and he was aware of wild yearnings and stirrings for he knew not what." (Chapter 7)
Buck hears the call of the wild.
- "He was a killer, a thing that preyed, living on the things that lived, unaided, alone, by virtue of his own strength and prowess, surviving triumphantly in a hostile environment where only the strong survive." (Chapter 7)
Buck reverts to his primitive nature.
- "He had killed man, the noblest game of all, and he had killed in the face of the law of club and fang." (Chapter 7)
Buck's killing of the Yeehats.
- "When the long winter nights come on and the wolves follow their meat into the lower valleys, he may be seen running at the head of the pack through the pale moonlight or glimmering borealis, leaping gigantic above his fellows, his great throat a-bellow as he sings a song of the younger world, which is the song of the pack." (Chapter 7)
The final sight of Buck.