Final answer:
In 'To Kill a Mockingbird', Scout and Jem found gum and Indian-head pennies in the Radleys' tree. These items from the knothole signify the beginning of a subtle communication between the children and Boo Radley.
Step-by-step explanation:
In chapters 4-7 of To Kill a Mockingbird, Scout and Jem found several items in the knothole of the Radleys' tree. Initially, they found two pieces of gum. Later on, they discovered two Indian-head pennies. As the story progresses, the knothole serves as a mysterious conduit for gifts that the children assume come from the reclusive Boo Radley.
The items found in the tree play a significant role in developing the relationship between the children and Boo Radley, suggesting a silent communication and understanding that begins to break down the myths surrounding the Radley house and its inhabitants.