The study of mosses is not only a practical feature that offers Alma a scope of scholarly focus upon which she can become expert, but the mosses themselves are also a symbol that mirrors the very nature of Alma and her world. Just as the estate of White Acre yields enough of interest to keep young Alma occupied, the tiny, intricate, and immense kingdoms of moss represent the entire complexity of the natural world, showing her all of its ruling truths, promises, and questions. Her mossy boulders are microcosms of the larger world that is only accessible through books or the reports of others. With the mosses, she can watch tiny continents that retreat or advance, colonies that engage in warfare, and whole civilizations that thrive or wither.

The mosses therefore represent a world that Alma can thoroughly explore and even conquer; they provide her knowledge, offer material evidence that she can measure and theorize, and also furnish questions that occupy her as well as the larger scientific world. Although she feels obligated not to leave White Acre or her father, the mosses provide a way for Alma to engage in useful work and contribute something to the field of knowledge.