How we cite our quotes:
Too late One Ear learned his mistake. Before they saw the cause, the two men saw him turn and start to run back toward them. Then, approaching at right angles to the trail and cutting off his retreat they saw a dozen wolves, lean and grey, bounding across the snow. On the instant, the she-wolf's coyness and playfulness disappeared. (3.8)
Here's one of the nasty laws out in the wild: the minute you lose your innocence is usually the minute you get killed. London definitely loves rubbing our noses in the deadliness of nature, no more so than when an innocent soul gets eaten.
Now that the terrible unknown had let go of him, he forgot that the unknown had any terrors. (7.16)
London seems to be saying that innocence is resilient here, at least in White Fang and maybe in all animals. Once they lose their fear, they forget they had it in the first place; it leaves no scars and they can presumably go on with their lives as if nothing had changed. Which actually sounds kind of nice.
Then all fight fled out of him. His puppyhood and the instinct of submission took charge of him. (9.6)
See, innocence is a long-term thing with animals. One moment he's all ready to rumble. The next, he's a puppy again. It sucks to be him at that moment, but it also shows how easily his innocence can rebound.