The Call of the Wild
How we cite our quotes:
For half a day this continued. Buck multiplied himself, attacking from all sides, enveloping the herd in a whirlwind of menace, cutting out his victim as fast as it could rejoin its mates, wearing out the patience of creatures preyed upon, which is a lesser patience than that of creatures preying. (7.29)
Buck’s superiority to other creatures is largely a result of his mental patience and determination.
From then on, night and day, Buck never left his prey, never gave it a moment's rest, never permitted it to browse the leaves of trees or the shoots of young birch and willow. (7.32)
Determination in the wild is linked with the kill, a necessary skill that Buck acquires as he adapts.