What is the importance of the Darryl Hicks Carnival in the novel, Ishmael: An Adventure of the Mind and Spirit?

An old-fashioned freak show, the Darryl Hicks Carnival acquires the protagonist, Ishmael, after he is evicted from his apartment. The narrator tracks the carnival northward to Plymouth, where he finds Ishmael being verbally tormented by children and reticent to talk. Eventually Ishmael agrees to finish the lessons from his barred cage, but is in bad physical shape by the time they finish. As the narrator schemes how to rescue his gorilla mentor, Ishmael dies of pneumonia. The Carnival packs up and moves on to its next venue and the narrator finds a few mementos in the trash the Carnival leaves behind.