What is the theme of chapter 2 Call of the wild?

Please help.

How does gatsby smile at nick? why is this important?

My cat and my dog like best friends

What is the effect of narrator's word choice on the tone of this passage? the words "my heart shrank within itself" create a fearful tone. the words "better-omened" set a hopeful tone. the words "wounded his fellow" develop a remorseful tone. the words "struck harsh upon my ears" suggest an irritated tone.