How has jacks appearance changed since he first arrived on the island?

Jack is described as something like a choir boy when the story begins;

"Inside the floating cloak he was tall, thin and bony; his hair was red beneath the black cap. His face was crumpled and freckled and ugly without silliness" (p.20)

By chapter three, Jack has a more wild appearance, but he won't completely transform into a savage until later in the novel. In Chapter 3 he dresses the part of the hunter.