The passage describes Buck after he has become capable of surviving independently in the wilderness. He no longer depends on people for food or protection, but hunts for himself and relies on his physical strength, experience and instincts. London presents this as a significant stage in Buck’s transformation from a domesticated dog into an animal able to live on its own terms in a demanding environment.

The language also reflects ideas about competition, adaptation and survival that influenced some writing in London’s period. The phrase “only the strong survived” presents nature as a severe contest in which weakness can carry serious consequences. Within the novel, however, Buck’s survival depends on more than physical force: he also learns, adapts and responds intelligently to changing conditions. The quotation therefore connects strength with self-reliance and adaptability while emphasising the harshness of the world Buck has entered.