She reared and struck at him as he climbed.

He was just out of reach.
Instantly she seized the tree, and with her huge teeth tore a great piece out of it with a crash.

Then she reared again, dug her claws deep into the bark, and began to mount it slowly, but as surely as a monkey.
Denys's evil star had led him to a dead tree, a mere shaft, and of no very great height.

He climbed faster than his pursuer, and was soon at the top.

He looked this way and that for some bough of another tree to spring to.