Answer and Explanation:
The paragraph to which this question refers is the following:
<em>He admitted, however, although with hesitation, that much of the peculiar gloom which thus afflicted him could be traced to a more natural and far more palpable origin—to the severe and long-continued illness—indeed to the evidently approaching dissolution—of a tenderly beloved sister, his sole companion for long years, his last and only relative on earth...</em>
<u>Even though what we have here is indirect speech - the narrator retelling Usher's words -, the author made sure to represent the way in which Usher himself was speaking. He was telling the narrator about his mental state and about a condition he believes he possesses (extreme sensory acuteness, according to him). </u><u>However, once Usher begins to reveal that this condition of his is related to his sister's disease and death, he seems to go out of breath. He interrupts himself, adding details in a hurried way, which is represented by the phrases enclosed by the dashes. Therefore, we can say the author structures these sentence in this way to show Usher's shortness of breath and rushed speech.</u>
