What are the motifs in The City Limits by Archie Randolph Ammons?

Fear is a recurring idea in the poem. In "The City Limits," fear is said to stem from the "breadth" of the physical world. In a sense, human fear seems to stem from the knowledge that humanity is outnumbered in the world. It is humans who have made up the idea that there is a difference between nature and humanity; when a poem like this one points out that all of the things in nature, down to the "dark work of the deepest cells," are "of a tune" with each other, then the prospect of being left outside of that majority can indeed be very intimidating.