When we talk about the symbols and meanings in the book, the first thing striking the eye is the novel’s title. A mockingbird is the core symbol of the story. As Atticus puts it, to kill a mockingbird is a sin. It is a harmless creature that doesn’t do one thing ‘but sings its heart out for us’. To kill it means to kill somebody pure and innocent. Since Tom Robinson is innocent, his sentence and eventual death is also a ‘killing of a mockingbird’.
The mad dog
It is unusual for the town people to see a mad dog in February. Especially because this dog is Tim Johnson, ‘the pet of Maycomb’, everybody seems shocked to see him mad and utterly dangerous. The dog symbolizes the people of Maycomb, who get angry and uncontrollable due to their ignorance and prejudices. These changes seem terrifying and ominous.
Mrs. Dubose’s camellias
The flower is the symbol of the old lady’s inner beauty and courage. At first, Jem hardly understands it, so he tears up the camellias. He also has a hard time to change his mind about the woman and the flowers. Finally, he understands Mrs. Dubose's reasons to be mean and he accepts the flowers and their value.
It is a symbol of the Scout’s freethinking and independence. She wears it in spite of public prejudices regarding what a girl should be wearing. Calpurnia and especially Aunt Alexandra want Scout to wear a dress instead of an overall. They want her to fit the public opinion about a proper girl behavior. For Scout to wear a dress means to change herself, to refuse of her favorite activities and in a way to stop being herself. When she is finally forced to put on a dress she feels herself humiliated and suppressed.