White Fang Part 2, Chapter 3: The Gray Cub
The young wolf is gray like his father, and all his brothers and sisters have their mother's reddish tinge. His eyes have not been open long, but he can see well, and he plays with his brothers and sisters. He has slept most of the first month of his life, but now he can see the walls of the cave. He knows nothing of the outside world, although he can see that one wall is different than the rest. This wall is the source of light, the mouth of the cave. His brothers and sisters always crawl towards the light, and the she-wolf always forces them back. In this way they learn that their mother can also punish as well as care for them. He learns that when he goes towards the light, his mother hurts him. He is a fierce cub and a meat-eater. He is the most aggressive of the litter, and growls louder than any of them. Every day, the light from the mouth of the cave calls to him.
"He was always striving to attain it. The life that was so swiftly expanding within him, urged him continually toward the wall of light. The life that was within him knew that it was the one way out, the way he was predestined to tread." Part 2, Chapter 3, pg. 48
He also knows that his father enters through the wall of light. Seeing him pass through, he tries to go through other walls, but simply injures his nose. He accepts disappearing into walls as something specific to his father.
Soon there comes a shortage of food, his mother no longer gives milk, and there is no meat. The cubs stay in a coma from lack of food. One Eye travels far to find food for the children, and the she-wolf eventually leaves them to also look for food. When the cub is able to eat and be strong again, he finds out he only has one sister left. Soon she does not move any more. The food does not come in time.
Later, after another famine, his father does not come back. The she-wolf knows why he doesn't return, but she has no way of telling the cub. She had found him near the lynx's lair, no longer alive. From that point on, she will always avoid that area of the forest.
"But the Wild is the Wild, and motherhood is motherhood, at all times fiercely protective whether in the Wild or out of it; and the time was to come when the she-wolf, for her gray cub's sake, would venture the left fork, and the lair in the rocks, and the lynx's wrath." Part 2, Chapter 3, pg. 50