This is a question I wish I would've asked in class a billion years ago....

In a college class in American Lit. we were discussing the Hemingway short story with the cat. I think it was a couple talking over tea or something and they saw a cat outside and talked about it.

The Prof. talked about symbols and then stated that the cat in that story is a symbol for a baby. In other words, the lady of the story talked about it because she wanted to have a baby.

The question is....how is/was this known? The Prof. offered it as a stated fact and, I believe that I've read that somewhere else, too. So...how would somebody who never heard this "fact" that's "generally known" come up with the fact that the cat is a symbol for a baby?

Thanks....