Which exerpt feom the call of the wild shows Buck entering into a new episode of his life

Even the insistent cough of the woman next to him wasn't enough to draw his eyes away from the tiny type of the ancient book its pages were brittle and felt like they could crumble at the slightest disturbance he noticed the musty odor if each page as he carefully it over.

What is the central idea in this advice from branch rickey to jackie robinson?  

Essay about how to keep environment clean and safe?