The tortoises also serve as an important symbol elsewhere. Some of Melville's dry humor comes across in the sentence, "[The tortoises'] crowning curse is their drudging impulse to straightforwardness in a belittered world." This clever line works on two levels. It can be taken literally—the tortoises suffer in the world because they are too dumb to go around objects; and it can be read metaphorically, pertaining to people who are too narrow-minded to overcome the "obstacles" that appear in their own "belittered world." It is a slight, wry nudge to those tortoises of the human world that refuse to go around problems when they can't go through them.