Final answer:
Alice Walker uses the rhetorical device of synecdoche in this excerpt, using physical remains of ancestors to represent the ancestral homeland.
Step-by-step explanation:
In this excerpt, Alice Walker uses the rhetorical device of synecdoche. Synecdoche is a figure of speech in which a part is used to represent the whole, or the whole is used to represent a part. In this case, when Walker refers to 'the bones and dust of our ancestors,' she is using the physical remains of the ancestors to represent the ancestral homeland as a whole. This device creates a powerful image and emphasizes the deep connection between the people and their homeland.